In order to clarify the different tolerance of cucumber germplasm to NaCl, the salt-tolerant material MC2065 and salt-sensitive material White cucumber were used to verify the appropriate concentration of 50, 100, 150, 200, and 250 mM NaCl. And nine physiological and biochemical indexes, including salt tolerance index, chlorophyll, and protective enzymes under NaCl treatment were used to evaluate the salt-tolerances of 21 germplasms. The results showed that 100 and 150 mM could be the appropriate concentration.The salt injury index of White cucumber was 35.94% in 100 mM NaCl, showing obvious damage to leaves, while that of MC2065 was 4.69% and showed no obvious damage. Under 150 mM, both showed obvious damage, more than half of leaves were withered for White cucumber, but less than half for MC2065. With cluster analysis, 21 germplasms were divided into 3 groups. The first group categorized as salt-tolerant germplasm, including ZQ3, N26-5-1, Shoushui 1, DRTJY-2, Laixi, Cuiyu, 20S077-1. The second group, including DJ04, DY-1, XY1, YY9123, M2XT, D1503, X805, was medium salt-tolerant germplasm. And the third group was salt-sensitive germplasm, which included F6-3-1, SJ11-1, XB23, 20S091-1, HLT-921h, AZ-1, DRT345. The trend of comprehensive scores of cucumber germplasm by the compoment analysis was basically consistent with that obtained by cluster analysis and seedlings survival rate. The study will provide references for investigating cucumber salt-tolerant mechanism and lay a foundation for the breeding of cucumber salt-tolerant varieties.

To explore the effects of high-energy heavy ion beam and X-ray radiations on the growth, development and physiological characteristics of rice seedlings, Japonica rice Kitaake seedlings were treated with high-energy heavy ion beam of 5~40 Gy and X-ray radiation of 10~80 Gy. The root length, shoot length, seedling height, plant height, tiller number, seed setting rate, 1 000-grain weight, photosynthetic characteristics, antioxidant enzyme activity and genetic polymorphism were investigated. The results showed that no matter with high-energy heavy ion beam or X-ray radiation, the root length and shoot length of rice seedlings showed a trend of decrease with the increase of irradiation dose, but the plant heights of surviving plants at mature stage were not different from those of the non-irradiated group. The seed setting rate and 1 000-grain weight of M₁ plant decreased with increasing dose, and showed a significant decrease at higher doses. When the relative root length was about 69% after radiation treatment, the two kinds of radiation had significant effects on the antioxidant system of the roots and shoots of seedlings in a short period of time. Compared with the non-irradiated group, the X-ray irradiation treatment group had higher chlorophyll content and lower F_v/F_m value, while the high-energy carbon ion beam irradiation group had no significant difference in chlorophyll content and F_v/F_m value compared with the non-irradiated group. The polymorphism rate of simple inter-repeat sequence (ISSR) in rice seedlings treated with 20 Gy high-energy carbon ion beam irradiation was 29.31%, and the ISSR polymorphism rate in rice seedlings treated with 40 Gy X-ray irradiation was 37.76%. The results of this study show that the M₁ biological effect of rice Kitaake seedlings treated by high-energy carbon ion beam and X-ray radiation are different. The recommended mutagen dosage range are 20~30 Gy for high-energy carbon ion beam and 30~40 Gy for X-ray.

Ethylene response factors play an important role in plant abiotic stress response. In order to understand the molecular mechanism of TaERF2 under waterlogging in wheat, the sequence characteristics of TaERF2 gene and its coding protein were analyzed, and the expression characteristics and prokaryotic expression of TaERF2 were detected in different waterlogging tolerant cultivars. The results showed that TaERF2 gene contained two exons and one intron encoded 355 amino acid sequences which had typical AP2/ERF conserved domain and YRG and RAYD motifs. The evolution and homology comparison analysis of AP2/ERF family transcription factors showed that TaERF2 belonged to group B2 of AP2/ERF family, which had high homology with Arabidopsis AtRAP2.12, AtHRE1 and rice OsSNORKEL1 and OsSNORKEL2. The promoter region of TaERF2 contained anoxic and anaerobic cis elements. It was speculated that TaERF2 might be a response gene to wet stress. After waterlogging stress, TaERF2 was specifically expressed in wheat roots. The expression was significantly up-regulated in the roots of waterlogging tolerant cultivar Ningmai 9, which reached the highest expression in 2-4h, and then decreased, but not up-regulated in the roots of waterlogging sensitive cultivar Zhengmai 1354. Prokaryotic expression showed that TaERF2 could respond quickly to stimulation induction, which was similar to the expression pattern of that in the root of Ningmai 9. The results suggested that TaERF2 plays an important regulatory role in wheat moisture tolerance, which provides reference for the study of AP2/ERF transcription factor in the molecular regulation mechanism of wheat waterlogging tolerance.

In order to clarify the changes and correlation between appecrances traits and intrinsic qualities of Olea europaea with different maturity, the fruits of Arbequina, Piculal, Ezhi-8, and Lecctno with six kinds of maturity were used as experimental materials in this study. The appearance indicators including fruit size, color, oil content, fatty acid composition, reducing sugar, total phenols, total flavonoids and other internal quality indexes were determined, and the correlation between each index were analyzed. The results indicated that four varieties indicators of Olea europaea were changed with maturity increase, among which the L* value, a* value, b* value was first increased and then decreased, oil content and transverse diameter were increased, longitudinal diameter was not changed significantly; Meanwhile, fruit shape index was decreased and transverse diameter was increased faster than longitudinal diameter, indicating that fruit was appearance gradually became round; The reducing sugar content was decreased first and then increased, total phenols and flavonoids content at the first maturity were significantly higher than those at the other five maturity, and the ratios of saturated fatty acid (SFA), monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid (PUFA) of Arbequina, Piculal and Ezhi-8 were closer to 1:1:1. There were significant correlation between oil content and the ratio of fatty acid, reducing sugar, total phenolic content, fruit shape index and transverse diameter of olive with different maturity, and correlation coefficients were 0.73 and -0.84, respectively. Additionally, the a^*value was significantly negatively correlated with reducing sugar content, and extremely significantly negatively correlated with total phenol and flavonoids content. Total flavonoid content was negatively correlated with SFA and PUFA, but positively correlated with total phenol content, MUFA, reducing sugar content, fruit shape index, L^* value and b^* value. Comprehensive variation and correlation analysis results showed that a^* value and total flavonoid content of Olea europaea could represent most of the indexes. This study provided theoretical basis for reducing the detection amount of fruit quality indexes, and collecting index data for subsequent mechanical harvest recognition system.

Huangxinwu is one of the main varieties cultivated in the middle and lower reaches of the Yangtze River, especially in Anhui province. To obtain high-quality new materials, this study used 0.2% (W/V) colchicine solution was used to treat the cotyledon growth points of diploid Huangxinwu seedlings, autotetraploid Huangxinwu plants was screened by morphological and cytological methods, and the agronomic characters and quality was analyzed. Morphological studys showed that tetraploid plants were giant in plant type, leaf, flower, and seed pod. The stomata in tetraploid leaves became were larger and the stomata density was decreased. Leawes of tetraploid had larger stomata and lower stomatal density. Cytological analysis showed that tetraploid plants had twice as many chromosomes as diploid plants. In terms of nutritional quality, the contents of cellulose and organic acid in tetraploid were significantly increased, the contents of chlorophyll and nitrate nitrogen were significantly decreased, while the contents of soluble sugar and soluble protein were not significantly changed. In addition, combined with the light response curve analysis results, the tetraploid is more adaptable to light intensity under strong light. The resistance of tetraploid to Botrytis cinerea was better than that of diploid. In this study, a new autotetraploid Chinese cabbage Huangxinwu with high yield and disease resistance was obtained, which provided a new germplasm resource for Chinese cabbage breeding.

To identify the GRAS gene family and analysis gene expression levels under exogenous hormones and abiotic stresses treatment in foxtail millet (Setaria italica). In this study, we performed a genome-wide identification of GRAS genes by bioinformatics method, analyzed the expression pattern under four hormones and two abiotic stresses with qRT-PCR, and developed molecular markers of SiGRAS23 based on the sequence differences. The results showed that there were 52 members of GRAS transcription factors in the whole genome of foxtail millet, the putative proteins are 362 to 734 AA in length with molecular weight from 39.81 to 100.09 kD and the isoelectric point from 4.85 to 9.53, most of them are hydrophilic proteins and 82.69% of them are acidic proteins. SiGRAS transcription factors were divided into ten subfamilies. Heatmap of FPKM values showed that the genes of each subgroup had obvious tissue expression specificity. The LISCL, DELLA and SHR subfamily genes have higher expression levels in leaves, stems and roots, respectively. PAT1 and HAM subfamily genes express in constitutive patterns, with the highest expression levels in leaves. The promoter region contains a variety of cis-acting elements responded to plant hormones and stress response. The gene expression levels were diverse even among members of the same subfamily under different hormones and abiotic stresses. Among them, seita.2g369400, belonging to PAT1 subfamily, was the most sensitive to six different treatments, while the expression level of some genes was very low in various tissues and organs, and hormones and abiotic stresses treatments. There were some differences in the gene sequence of SiGRAS23 between Aininghuang and Jingu 21, which are the parents of AJF₅ genetic population. The marker D8-1 developed with SiGRAS23 was closely linked with plant height. This study laid a foundation for analyzing the functions of SiGRASs involved in hormone signal transduction and stress response. The molecular marker developed by SiGRAS23 can be used to select variations in plant height of foxtail millet germplasm in the future.

To investigate the effects of nitrification inhibitor application in reduced nitrogen rate on the leaf physiological characteristics in grain filling stage of summer maize, normal nitrogen(N) rate, N application reduced with or not nitrification inhibitor treatments were conducted to analyze the variation of SPAD, fluorescence characteristics, key enzyme activity about N metabolism of ear leaf, yield and N efficiency in this study. The result indicated that N reduced by 20% adding nitrification inhibitor treatment could increase the kernel number, and grain yield in this treatment was 11.59 t·hm^-2, achieved the normal N level. Compared with normal N rate treatment, N reduced by 30% and 20%, with or not nitrification inhibitor, significantly increased N efficiency. Nitrogen uptake efficiency and nitrogen utilization efficiency were significant different in each treatment, respectively. Highest nitrogen uptake efficiency was found by 0.72 kg·kg^-1 in N reduced by 30% and highest nitrogen utilization efficiency was obtained by 72.23 kg·kg^-1 in N reduced by 30% adding nitrification inhibitor treatment. In the grain filling stage, N reduced by 20% adding nitrification inhibitor treatment got the higher SPAD, Fm and PI and enhanced activity of NR and GS. Thus, in this study, N reduced by 20% adding nitrification inhibitor could strengthen the N metabolism capacity, coordinate the relation of N and C, increase N efficiency and grain yield, to reduce cost and increase efficiency, and could be theoretical basis for widely promoting nitrification inhibitor in the maize production of this region.

The purpose of this field experiment is to explore the effect of foliar spraying KH₂PO₄ after anthesis on the physiological characteristics of wheat root and grain yield under high temperature stress during grain filling period. The experiment was designed with four different foliar spraying treatments, i.e. water (NT), water + high temperature stress during grain filling (NHT), KH₂PO₄ solution (PT), KH₂PO₄ solution + high temperature stress during grain filling (PHT), respectively. To investigate the effect of spraying KH₂PO₄ on root vigor, antioxidant activity, malondialdehyde (MDA) content, net photosynthetic rate (Pn) of the flag leaf, dry matter accumulation and distribution at maturity, as well as grain yield in wheat under high temperature stress during the grain filling period. The results showed that the root vigor, superoxide dismutase (SOD) and peroxidase (POD) activity before high temperature stress treatment were significantly increased by foliar spraying of KH₂PO₄, while the MDA content was significantly decreased. The root vigor was significantly decreased after being subjected to high temperature stress, however, the decline in spraying KH₂PO₄ treatment was significantly reduced due to the higher SOD, POD and catalase (CAT) activity in the roots, and the MDA content in NHT was significantly higher than NT, NT was significantly higher than PHT, and PT was significantly lower than PHT. Spraying KH₂PO₄ after anthesis significantly improved Pn of flag leaf during the grain-filling period, and alleviated the harm of high temperature stress on the photosynthetic capacity of leaf. At maturity, the dry matter accumulation amount in PT was significantly higher than that in PHT and NT, while no significant difference was found between PHT and NT. The amount was the lowest in NHT. The dry matter distribution amount to the grain for PT was the most. Owing to the significant increase in thousand-kernel weight, spraying KH₂PO₄ after antheis significantly improved the grain yield, while compared with NHT, the grain yield of NT, PHT and PT was increased by 17.8%, 18.9% and 26.7%, respectively. In conclusion, foliar spraying of KH₂PO₄ after anthesis could delay senescence in wheat roots, enhanced the resistance of roots to high temperature stress during grain filling period, improve the accumulation of dry matter of plants at maturity, and reduce grain yields loss. This study provides a theoretical basis for spraying KH₂PO₄ after anthesis in wheat to alleviate the harm of high temperature stress on wheat production.

In order to explore whether the mutation of Tetrastigma hemsleyanum Diels et Gilg(T.hemsleyanum) Zeqing 1 produced varied pharmacological component, the physicochemical quality such as soluble polysaccharides, total ketones, total saponins, total phenols, soluble proteins, minerals and free amino acids of 26 samples were evaluated and their correlation analysis were performed, and the mutated sites of ITS sequences of 26 samples were detected. The results showed that 11 excellent mutants 103, 107, 109, 112, 113, 125, 126, 127, 130, 131, 132 derived from Zeqing 1 were selected. The interspecific homology, overall mean distance, and between group mean distance among groups between Zeqing1 and its 23 closely related species were 49%, 0.54, and 0.993 respectively. Intraspecific homology, pairwise distance and mean distance within groups among mutants were 93%~99%, 0.006 40~0.116 96 and 0.060 70 respectively. The DNA barcode of mutants based on ITS species identification was successfully constructed. In this study, 11 mutants with application value of diversified directional breeding were screened which provide germplasm resources for solving the scarcity and degradation of T. hemsleyanum. Meanwhile, the mutant group derived from Zeqing 1 was successfully identified and distinguished from other related cliff climbing species based on ITS molecular markers, and the mutation sites of the mutant group were screened, which provided the technique support for the evaluation of germplasm resources of T. hemsleyanum mutants.

To clarify the effects of storage time and low storage temperature on the nutrition quality of rapeseed stem， two oil-vegetable rapeseed cultivars Zheyou 51 and Zheyouza 108 were used as materials. 3 storage times （stored at 4 ℃ for 1， 2， 3 d） and 3 storage temperatures （stored at -20， -40， -80 ℃ for 10 d） were set， and the contents of sugars， vitamins， cellulose and lignin during storage were analyzed. The results showed that vitamin C and vitamin B₁ showed a rising trend first and then falling in two varieties， while vitamin B₆， fructose， sucrose and cellulose showed an upward trend with the extension of storage time under 4 ℃. Vitamin E were raised in Zheyouza 108， while it increased first and then decreased in Zheyou 51. The starch content gradually decreased in two varieties. Paraffin section staining results showed that the cellulose area in Zheyou 51 and lignification area in Zheyouza 108 were increased with the extension of storage time. Under different storage temperatures， the content of all the nutrition except cellulose were the highest in fresh sample， while cellulose contents reached the highest in -20 ℃. Fructose， sucrose and cellulose contents can match the fresh level at -80 ℃ in two varieties， while the content of vitamin B₁ and E were better under -40 ℃ in Zheyou 51. In conclusion， the appropriate shelf life of rapeseed stem should be within 2 d when storing at 4 ℃. For low storage temperature， -40 ℃ and -80 ℃ were better than -20 ℃. The results of this research provides a theoretical basis for daily storage and consumption of rapeseed stem and the multi-functional utilization of rapeseed.

Rice milling quality directly affects its market value. To understand the genetic basis of rice milling quality, two sets of reciprocal introgression lines and a set of recombinant inbred lines derived from geng variety Xiushui09, and xian variety IR2061 were evaluated for milling quality at Wenzhou and Sanya. A linkage map containing 145 SSR markers with length of 1 567.8 cM was constructed. The average background recovery percentages were 90.15% and 85.82% in Xiushui 09 and IR2061 introgression lines, respectively. The brown rice rate (BRR) and milled rice rate (MRR) were no significant difference between the two parents, while Xiuhui09 had higher head milled rice rate (HMRR) than IR2061. All of BRR, MRR and HMRR showed continuous distributions in the three populations, and there were significantly positive correlations among BRR, MRR and HMRR. A total of 29 main-effect QTLs (M-QTLs) and 20 epistatic QTLs (E-QTLs) were identified under the two environments. Among them, six QTLs were simultaneously identified in the two backgrounds, two QTLs stably expressed across two environments, and ten QTLs interacted with environments, suggesting that genetic background and environment had large effects on QTL detection of milling quality. Moreover, regions of RM432~RM11 on chromosome 7, RM80~RM458 on chromosome 8, and RM257~RM278 on chromosome 9 had pleiotropic effects on all the three milling quality traits, the alleles of Xiushui 09 at all regions increased milling quality. Our results provide valuable gene resources for improving rice milling quality by molecular breeding.

To generate new two-line male sterile lines which can be used to breed elite hybrid varieties, a japonica photoperiod/temperature-sensitive male sterile (PTGMS) line Jiang 79S was generated by anther culture and irradiation. Firstly, a japonica PTGMS line S79 was generated through another culture of F₁ hybrids derived from Peiai 64S and japonica line H179. Then its dry seeds were treated by high energy carbon ion beam, a mutant line GS79 (Jiang 79S) with changed heading date was obtained. Under the long-day condition, Jiang 79S started heading ~7 days earlier than S79, while under the short-day condition, Jiang 79S headed ~5 days later than S79. Jiang 79S showed partial to complete fertility after the September 8 and set seeds in Jiaxing. While in Lingshui, Jiang 79S showed normal fertility with seed set rates higher than 80%. A photoperiod/temperature sensitivity test in phytotron showed that the fertility transition temperature was lower than 23.5 ℃ under long-day condition. The whole genome sequencing of GS79 showed that besides the photosensitive male sterile genes pms1 and pms3 derived from its progenitor Nongken 58S, it also carries rice blast resistance genes pi21, Pia, Pid3 and Pita, which corroborates its high seedling blast resistance. The inter subspecific hybrid rice “Jiangliangyou 7901” from Jiang 79S has completed the national new variety trial test and been nationally approved. The results provide methods for breeding new two-line male lines by comprehensive use of anther culture and irradiation mutation technology.

Improving the zinc(Zn) bioavailability of cereal edible part is an effective measure to solve Zn deficiency of human. A field experiment was conducted with ZD958 and GSY66 of maize hybrids. Three nitrogen rates(90, 180 and 225 kg N·hm^-2) and two foliar zinc application(0 and 4.5 kg·hm^-2 ZnSO₄·7H₂O) were set to analyse the variation of the maize grain yield, N and Zn concentration and photosynthetic characteristics of leaf in the grain filling stage of maize, to evaluate the effect of N and Zn fertilizer application on the Zn nutrition of maize grain. The results showed that, compared with N application of 90 kg·hm^-2, N rate with 180 and 225 kg·hm^-2 had the higher leaf SPAD, and NR, GS, SOD, POD and CAT activity after silking, PSⅡ comprehensive performance index(PI) in the later grain filling, and the lower content of MDA after silking. Foliar Zn increased leaf CA, SOD, POD and CAT activity after silking and SPAD, PI in the later grain filling and decreased content of MDA. Between two cultivars, higher leaf SPAD, Fo and Fm in the later grain filling was obtained in GSY66 and higher leaf PI in the early grain filling, NR, CA, SOD and POD activity after silking was found in ZD958. Grain yield was 8.55 t·hm^-2 with N application of 90 kg·hm^-2 and increased with N application increased. The N content with 180 kg·hm^-2 had the highest grain N concentration (14.85 g·kg^-1). Grain Zn concentration was higher in the N application of 90 and 180 kg·hm^-2, averagely 27.2 mg·kg^-1, compared with 225 rate kg·hm^-2. Compared with no Zn application, foliar Zn had no effect on the grain yield, but increased the N and Zn concentration of grain by 11.7% and 18.0%, respectively. Relative to GSY66, ZD958 had improved grain yield by 3.8% but decreased N and Zn concentration by 11.9% and 5.3%, respectively. These results suggested that N application with 180 kg·hm^-2 and foliar ZnSO₄·7H₂O with 4.5 kg·hm^-2 could enhance maize leaf SPAD and fluorescence parameter, and increase the enzyme activity of nitrogen and zinc metabolize and oxygen free radical scavenging system, thus to reduce the damage of membrance lipid peroxidation and promote the absorption and accumulation of N and Zn in the maize grain. The result could provide a theoretical guide for enhancing the Zn biofortification in the maize production.

In order to explore the protective effect of Artemisia argyi essential oils (AAEO) on H₂O₂-induced oxidative damage of carp liver, the oxidative injury model of carp liver was established using H₂O₂ as an inducer, and the diets containing 0.1, 0.2, and 0.4 g·kg^-1 AAEO were fed to protect it. After treatment for 30 days, the serum and liver were collected to detect the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidases (GPx), and the contents of total protein (TP), albumin (ALB), and malondialdehyde (MDA). The structure of liver tissues in carp was observed by histological method. The relative expression levels of Cu/Zn SOD, Mn-SOD, GPx, CAT, and transcription factor (Nrf2) were detected by quantitative real-time PCR. The results showed that the exposure of H₂O₂ for 30 days could increase the activities of ALT and AST, while decrease the contents of TP and ALB in serum, H₂O₂ could reduce the activities of SOD, CAT, and GPx, while elevate the MDA concentration in serum and liver. H₂O₂ could cause the pathological damage and inhibit the expression of antioxidant genes of liver tissues. AAEO could inhibit the increase of ALT and AST activities and the decrease of TP and ALB contents, improve the antioxidant capacity of the body, relieve the pathological damage of liver tissue, and induce the expression of antioxidant genes by activating Nrf2. In conclusion, AAEO has a certain protective effect on H₂O₂-induced oxidative damage of carp liver, which can provide basic information for further exploring AAEO as a green and safe antioxidant.

For revealing the regulatory molecular mechanism of bitter gourd fruit ripening, the flesh tissue of inbred line E12201-e1 at different maturity stages was used to construct yeast two-hybrid cDNA library by All-Direct method. The library capacity was 1.25×10⁷ CFU (Colony-Forming Units), recombination rate was 100%, and the average length of inserted fragment was longer than 1 200 bp. The library has high quality and it was conformed to the standard of library construction. The bait vector pGBKT7-McRPF was constructed and it has no self-activation activity. Twenty-nine initial positive clones were screened from the library using the co-transformation method. After sequencing and BLAST comparison analysis, 12 proteins that could interact with McRPF were finally identified. This work provides an important basis for studying the regulation mechanism of McRPF on the fruit ripening of bitter gourd.

To explore the panicle-grain structure of high-yield hybrid rice varieties in the water-logged paddy fields of southern Sichuan, 36 new medium hybrid rice varieties were used as materials to study the yield formation characteristics of high-yield varieties from 2018 to 2020. The tested rice varieties had passed national regional trials on the upper reaches of Yangtze River or regional trials in Sichuan Province. This work was conducted at 5 representative ecological sites, such as Jiang'an, Fushun, Longchang, Luxian and Nanxi, and high-yield cultivation techniques for large-scale production of medium hybrid rice and ratooning rice were adopted. The results showed that there are 16 varieties with a yield of more than 11 000 kg·hm^-2 in two seasons, such as Nei5you 907, Neixiangyou 138, Neixiangyou 103, etc. F value of multiple regression analysis of panicle and grain characters in the first season on its yield reached a significant or extremely significant level. F value of multiple regression analysis of ratooning rice yield was extremely significant (F value=22.18, n=180), and the relationship with the total yield of the two seasons was extremely significant (F value=14.65, n=180). Selecting 43 groups of high-yield data of the main rice, ratooning rice and two seasons with total yield higher than 10 000 kg·hm^-2, 4 000 kg·hm^-2 and 13 500 kg·hm^-2, respectively, a very significant negative correlation was found between rationing rice yield and the main rice yield (y=12 161-0.867 6x, r=0.557 2). The big-spike cultivars showed relatively weak regeneration ability and high yield of main crop, while the quantitative spike type varieties had strong regeneration ability and high yield of two seasons. The panicle grain structure of main crop with high total yield in two seasons. The effective panicles were 2.307 2~2.578 5 million·hm^-2, the grains per panicle were 167.50~194.44, the seed setting rates were 78.80%~90.79%, and 1 000-grain weights were 22.60~29.33 g. The findings provide a new scientific basis for the selection of high-yield varieties and the establishment of cultivation techniques for the large-scale production of medium hybrid rice and ratooning rice in southern Sichuan.

In order to explore effects of different application methods of starter phosphate fertilizer on maize growth and yield, a field experiment was set up with three treatments (starter phosphate fertilizer applied by drip application (T1), hole application (T2), and no starter phosphate fertilizer (CK)) to investigate the effects of different application methods of starter phosphate fertilizer on maize growth, nutrient uptake and yield composition. The dose of the starter phosphate fertilizer was P₂O₅ 30 kg·hm^-2. A rhizo-box experiment was conducted with treatments: drip application (P1), hole application (P2) and no starter fertilizer (CF), to study the spatial distribution of the starter phosphate fertilizer in the soil, and the starter phosphate fertilizer rate was P₂O₅ 0.2 g·kg^-1 soil. The results indicated that T1 and T2 treatments significantly increased the total root length, the root surface area, the shoot and root biomass and the N, P and K nutrient uptake of maize at four-leaf stage and six-leaf stage. At the six-leaf stage, compared to CK, the root length in T1 and T2 increased by 21.10% and 30.35%, the root surface area increased by 23.48% and 29.20%, and the shoot and root biomass increased by 31.24% and 52.38%, 33.61% and 57.81%, respectively. Compared to CK, T1 and T2 promoted nitrogen, phosphorus and potassium uptake, and promoted the transfer of nutrients from vegetative organs to reproductive organs. From the silking stage to the mature stage, compared to CK, the amount of nutrient transfer of nitrogen, phosphorus, and potassium in T1 and T2 increased by 29.75 kg·hm^-2 and 44.73 kg·hm^-2, 10.76 kg·hm^-2 and 14.65 kg·hm^-2, 2.20 kg·hm^-2 and 24.67 kg·hm^-2, respectively. The ear length, the grain ear row number, and the yield and partial productivity of phosphorus fertilizer of maize followed the order of T2>T1>CK, while the bald tip length of maize had a T2<T1<CK arrangement. In P1 treatment, the available phosphorus content was mainly distributed at a depth of 0~9 cm and at a horizontally distance of 0~10 cm in the soil, while in the P2 treatment, it was mainly distributed at the depth of 6~15 cm and at a horizontal distance of 0~6 cm in the soil. In conclusion, the starter phosphate fertilizer promoted the growth and construction of the root system of maize at the seedling stage, thus providing an advantage for the maize's nutrient absorption of nitrogen, phosphorus, and potassium in the seedling stage and enhancing nutrient transfer to the reproductive organs at the reproductive stage, and further increasing maize yield. The hole application of the starter phosphate fertilizer showed better effects than drip application, mainly due to the deeper and more intensive distribution of available phosphate nutrients in the soil. Overall, this study provides an experimental basis for the rational and efficient application of starter phosphate fertilizer in maize production.

In order to explore biological effects of ⁶⁰Co-γ ray radiation on Medicago polymorpha seeds, in this study, dried seeds of Medicago polymorpha were treated with different doses (0, 400, 600, 800, 1 000 and 1 200 Gy). The germination rate, plant survival rate, seedling height, number of branches, number of flowers and number of pods were measured, and the semi-lethal dose (LD₅₀) of dried seeds was calculated by linear regression equation. The results showed that radiation dose of 400 Gy could significantly increase the germination rate of Medicago polymorpha seeds, while with the increase of radiation dose(400~1 200 Gy), the germination rate decreased. The radiation dose was significantly negatively correlated with survival rate, seedling plant height and number of branches; Low dose (≤600 Gy) could promote seed germination, plant growth and pods yield of bur clover, while high dose (>600 Gy) inhibited growth and fruiting of Medicago polymorpha seeds; and the semi-lethal dose of radiation to dried seeds of Medicago polymorpha was 580 Gy. This research provides a reference for mutation breeding of Medicago polymorpha.

The current study aims to characterize the potential relationship between grain quality parameters and yield related traits, including yield components and morphology traits, of wheat varieties differ in gluten compositions under rain-fed condition. During the three wheat growing seasons in 2017-2020, five strong gluten wheat varieties and eleven medium gluten wheat varieties from the Huang-Huai-Hai region were planted in field trials in Shandong province. Harvested grains were analyzed using near-infrared spectroscopy to determine water absorption, grain hardness, test weight, Zeleny sedimentation value, protein content, wet gluten content, dough development time, dough stability time, and extension and maximum resistance of dough. In addition, grain morphological traits such as grain length, grain width, grain thickness and grain area were measured through seed image analysis. Results showed that the sixteen varieties could be classified into five groups by cluster analysis based on the general quality index. The highest quality index was found for group Ⅴ varieties (Shiluan 02-1, Jimai 20 and Taikemai 33). Among the five strong gluten varieties, Jimai 20 displayed the highest yield. For the eleven medium gluten wheat, Yannong 999, Taimai 1918 and Yannong 173 had significantly higher yield than the others, with Taimai 1918 displaying a superior and stable grain quality. Grain morphology traits showed a positive correlation with thousand grain weight (TGW), while both grain morphology traits and TGW showed negative correlations with grain quality traits. In conclusion, Jimai 20 and Taimai 1918, representing the strong and medium gluten varieties, respectively, were superior in yield and quality and suitable for planting in the rain-fed condition of eastern Shandong province. This study also showed that near-infrared spectroscopy and seed image analyses are effective techniques for wheat quality evaluation. The results of the current study provide guidelines for both the selection and quality analysis of high yield and high quality wheat varieties in eastern Shandong province.

The purpose of this experiment is to determine the optimal concentration and time of EMS treatment of grain sorghum， and to create new germplasm of grain sorghum. In this study， the parental lines 2055B and 10125 of grain sorghum were treated with ethyl methanesulfonate （EMS） with different times and concentrations， and investigated the effects of EMS mutagenesis on agronomic traits such as seedling emergence， leaf color， leaf shape， panicle shape， fertility and growth period. The results showed that the emergence rate， seedling survival rate and seed setting rate of the two grain sorghum parent lines decreased with the increase of treatment time and concentration， while the mutation rate increased with the increase of treatment time and concentration.The same level of treatment had different inhibitory effects on the two parents， and the inhibitory effects of the restorer line 10125 on the emergence rate， seedling rate and seed setting rate were lower than those of the maintainer line 2055B. Considering the emergence rate， seed setting rate and mutation rate， the optimal mutagenesis treatment time and concentration of 2055B were 14 h and 0.25%， and the optimal mutagenesis treatment time and concentration of 10125 were 14 h and 0.3%. We obtained mutant material by observing， identifying and screening M₂ phenotypes， such as early maturity， dwarf， tiller， and etc. And a mutant library of grain sorghum was preliminary constructed， which can provide new germplasm and basic materials for sorghum breeding and functional gene mapping.