General combining ability （GCA） is an important index to evaluate the utilization value of parental inbred lines. In order to analyze the genetic mechanism of combining ability of maize， 537 hybrid combinations obtained from NCII genetic mating design were used as materials， seven multi-locus genome-wide association study （MGWAS） methods were used to identify significant loci for GCA of kernel row number， kernel length， and kernel width in Xinxiang， Zhoukou， and combined environment， combining with 11 734 high-quality single nucleotide polymorphism （SNP） markers obtained from the maize 5.5K liquid breeding chip. Based on MGWAS， five genomic selection methods were used to predicting the GCA effects. The results showed that 46 SNPs were detected and significantly associated with GCA of kernel row number and two kernel traits （P<8.52×10^-7）. Among them， ten loci were detected using two-to-five MGWAS methods simultaneously， and eight SNPs were co-located in at least two environments. Six SNPs （1_43440622， 2_69742504， 2_71037706， 2_197716855， 5_219239213， and 8_134634317） were both environment-stable and MGWAS method-stable loci， which were important loci controlling the GCA effects of kernel row number and kernel traits. The prediction accuracy of GCA for kernel row number and kernel width was high when using five random effect models， with a value of 0.62~0.74， and the prediction accuracy of GCA for kernel length was low， with a value of 0.28~0.45. In most cases， adding significant SNPs identified from different MGWAS as fixed effects into genomic best linear unbiased prediction(GBLUP) and reproducing kernel Hilbert space(RKHS) improved the prediction accuracy of GCA for kernel row number and two kernel traits in the three environments， with the percentage increase of 0.66%~15.96% for kernel row number and kernel width and 9.26%~83.05% for kernel length. The results of this study provide important gene information and technical guidance for subsequent gene function verification and genomic selection-assisted breeding of key loci.

Phytoene Synthase 1 （SlPSY1）， a key rate-limiting enzyme of carotenoid synthesis， directly affects the accumulation of carotenoids in tomato fruit. We constructed and transformed the bait vector pSlPSY1pro-AbAi into the yeast cell to explore the transcriptional regulation of SlPSY1. Then， the AP2/ERF family transcription factor SlJERF1 and 10 other proteins were screened by yeast-one-hybrid experiment using the yeast hybrid cDNA library built by mixed tissue of tomato. Subsequently， the sequence of SlJERF1 gene was cloned and the recombinant vector pGADT7-SlJERF1 wasconstructed. The molecular interaction between SlJERF1 and SlPSY1 promoterwas varified through yeast-one-hybrid point-to-point test. The results showed that the yeast in the control group could not grow normally under 150 ng·mL^-1 Aureobasidin A （AbA）， while the yeast transformed with SlJERF1 could grow normally， indicating the interaction between SlJERF1 and the promoter of SlPSY1 gene. This result provides an important theoretical basis for the regulatory network of carotenoid synthesis， and confers new ideas for further study in the future.

In order to explore the biological function of the FaGI gene in tall fescue. In this study， yeast two-hybrid， bimolecular fluorescence complementation and co-immunoprecipitation were used to explore the proteins interacting with FaGI， and the overexpression vector p1300-FaGI was transformed into Arabidopsis thaliana by an Agrobacterium-mediated method， and the FaGI transgenic Arabidopsis lines were obtained. The wild type Col-0， overexpression FaGI gene lines and gi mutant of Arabidopsis thaliana were used for transcriptome sequencing and observing flowering performance. The results showed that the FaCO protein interacting with FaGI was screened by yeast two-hybrid method， and the interaction between FaGI and FaCO in vivo and in vitro was proved by bimolecular fluorescence complementation and co-immunoprecipitation. The flowering time of Arabidopsis plants overexpressing the FaGI gene was about 1.24 days earlier than that of wild-type Col-0. Differentially expressed genes （DEGs） of 1 963 and 92 were screened by comparing FaGI-OE and gi with WT， respectively. Compared with wild-type plants， the differentially expressed genes of overexpression FaGI lines were enriched in biological processes and metabolic pathways related to growth and development， photoperiod pathway， hormone synthesis and signal transduction， and carbon metabolism. In conclusion， FaGI affects the expression of photoperiod pathway-related genes， and overexpression of FaGI promotes flowering in Arabidopsis under long-day light conditions. At the same time， the function of FaGI are diverse and complex， which can be used as target genes for molecular breeding of tall fescue. The results of this study laid the foundation for revealing the function of FaGI gene and its regulatory network.

Tomato brown rugose fruit virus （ToBRFV） belongs to the genus Tobamovirus in the Virgaviridae family and is classified as a quarantine virus in China， posing a serious threat to the safety of tomato production. Signal transduction system plays an important role in plant disease resistance， and phospholipid signaling is crucial in the process of extracellular resistance signal transduction. Phospholipase C （PLC） is critical in the transmembrane signaling of the phospholipid signaling system. In this study， we first identified 10 tomato PLC genes based on bioinformatics， including seven phosphati-dylinositol-specific phospholipase C （PI-PLC） and three non-specific phospholipase C （Non-specifc -PLC， NPC）， the seven PI-PLC PLC proteins have three core structural domains （PLC_X c， PLC_Y c， C2） and an EF_hand-like structural domain， and the three NPC proteins only have a phosphoesterase structural domain. 10 tomato PLC proteins can be divided into seven branches according to their structural similarity， namely NPC1， NPC2， NPC6， PI-PLC2， PI-PLC3， PI-PLC4 and PI-PLC6. In addition， the 10 tomato PLC secondary structures were similar in proportion， but there were significant differences in tertiary structures. Co-linearity analysis showed that there were 3， 12 and 16 pairs of co-linear relationships between the distribution of tomato PLC genes and rice， Arabidopsis and Raymond-type cotton PLC genes. Finally， to clarify which tomato PLCs are involved in the plant defense response against ToBRFV， this study examined the relative expression levels of the PLC gene family after ToBRFV inoculation by transcriptome sequencing， and the results showed that SlNPC1， SlNPC6 and SlPLC4 were expressed at higher levels in the ToBRFV-inoculated samples， while the expression levels of other PLC genes were reduced after ToBRFV inoculation. This study lays the technical and theoretical foundation for tomato ToBRFV resistance research and breeding.

Mulching technique is a widely used agricultural technology. The traditional plastic film currently in use brings huge economic benefits， but also induces serious ecological pollution problems and affects the sustainable development of agriculture， so the development of environmentally degradable mulching films is an inevitable trend. This study systematically describes the research progress and application status of the preparation materials， preparation technologies and products of photodegradable mulching film， biodegradable mulching film， photo/biodegradable mulching film， liquid mulching film and plant-fiber mulching film at home and abroad， as well as the advantages and shortcomings of the five types of degradable mulching films， and provides an outlook on the research direction and development prospects of plant-fiber mulching film. The results of this study provide a theoretical basis for further development of green， environmentally friendly and completely biodegradable agricultural mulching films to promote green and sustainable development of agriculture.

Over past two decades， the application of nuclear techniques has been integrated into many aspects of scientific research and production practice in food and agriculture， and nuclear techniques are unique and irreplaceable in some areas. This review provides a comprehensive overview of the latest developments and major achievements from the nuclear application in major fields of food and agriculture around the world. The application status and innovative development of nuclear techniques in the fields of animal production and health， food safety and control， plant mutation breeding and genetics， water and soil management and agricultural environment， and insect pest control were reviewed emphatically. Considering many severe global challenges faced by the food and agriculture around the world， the authors discussed and showed the prospects and strategic priorities of nuclear application in food and agriculture.

In order to explore the suitable fertilization formula of Lonicera japonica Flos in the Loess Plateau， the ‘3414’ experimental design was used. The optimum formula of nitrogen， phosphorus and potassium fertilizer was screened by yield and index component content. After the initial determination of the best fertilization treatment， four treatments were set up， that is， organic and NPK combined application group （OF+NPK）， single application of organic fertilizer group （OF）， single application of NPK fertilizer group （NPK） and no fertilization control group （CK） were collected for soil physico chemical properties and bacterial abundance detection. Spearman correlation analysis was performed on soil bacterial abundance and physicochemical properties， as well as L. japonica Flos yield and quality. The results showed that N₂P₂K₂ treatment， apply N： 30 g·plant^-1， P₂O₅：18 g·plant^-1， K₂O： 14 g·plant^-1 could make the yield per plant up to 229.26 g. The fertilizer effect equation showed that the recommended fertilization amounts of N， P₂O₅ and K₂O were 19.5~30.0， 12.6~18.0 and 13.3~16.8 g·plant^-1， respectively， and the yield per plant was 198.2~223.9 g. The results of soil microecology detection showed that the contents of available phosphorus， available potassium and organic matter in the group of OF + NPK were the highest， and significantly higher than those in CK and NPK. At the same time， the microbial community abundance in soil was significantly higher than CK group. Correlation analysis showed that Thermoleophilia， Gemmatimonadetes and Dehalococcoidia were the main beneficial bacteria in soil， which could positively regulate the yield and index component content of L. japonica Flos. The results of this study provide a theoretical basis for improvement of fertilization methods and development of special fertilizers in the new producing areas of L. japonica Flos in the Loess Plateau.

The ATP-binding cassette subfamily G （ABCG） plays a crucial role in the transport of substances in plant. In order to explore the molecular characteristics， expression patterns and regulatory relationships of ABCGs in moso bamboo （Phyllostachys edulis）， bioinformatics methods were used to identify the gene members of ABCG subfamily in moso bamboo. Moreover， the comprehensive analysis of the gene structure， physiochemical properties of protein and phylogenetic relationship was conducted， and the gene expression patterns were analyzed by quantitative real-time PCR （qRT-PCR）. Furthermore， the regulatory relationship between transcription factors and ABCG gene was verified by yeast one-hybrid assay. The results showed that there were 77 ABCGs identified inmoso bamboo （PeABCG1~PeABCG77）. A variety of hormone， abiotic stress response elements were found in the promoters of PeABCGs， among which the ABRE element in response to the abscisic acid （ABA） was the most， and appeared in the promoters of 74 PeABCGs. Phylogenetic analysis showed that PeABCGs were divided into white-brown complex （WBC） and pleiotropic drug resistance （PDR） subgroups， which were closely related to those of rice. The results of qRT-PCR demonstrated that six of seven PeABCGs associated with ABA transport were up-regulated under ABA treatment， whereas PeABCG34 was undetected. All the expressions of seven PeABCGs were induced by low temperature. The expression of two PeABCGs was inhibited， while those of other five genes were induced with different levels of drought treatment. Besides， the expressions of PeABCG15 in shoots was continuously up-regulated with the increasing degree of lignification， consistent with the expression trend of PeKNAT3 and PeMYB42 involved in regulating lignin synthesis. It was confirmed that PeKNAT3 and PeMYB42 could bind to the promoter of PeABCG15 by yeast one-hybrid assay. These results suggested that PeABCGs may participate in the resistance of moso bamboo in two ways： ABA-mediated and non-ABA-mediated， among which PeABCG15 was induced by ABA and may be involved in stress resistance by promoting lignin synthesis. These findings would provide references for revealing the biological functions of ABCG in moso bamboo.

To investigate the expression of Collagen1 and Collagen3 in pulmonary fibrosis tissue of yak and clarify the roles of Collagen1 and Collagen3 in pulmonary fibrosis process of yak. The normal and fibrosis lung tissue of yak were collected and divided into control group and experimental group. HE staining， Masson staining and transmission electron microscope were used to observe the pathological changes of lung ultrastructure and fibrosis state； qRT-PCR， Western-blot， immunohistochemistry and immunofluorescence staining were used to detect the expression of Collagen1 and Collagen3 genes and proteins in groups. The results showed that the yak lung tissue structure of the control group was intact， the alveolar septum was normal and there was no inflammatory exudate in bronchial lumen and alveolar cavity. while in experimental group， lung tissue showed necrosis， nuclear fragmentation and dissolution， severe hemorrhage and extensive pulmonary edema. The expression of Collagen1 in experimental group is higher， while the expression of Collagen3 is lower than that in control group. In experimental group， Collagen1 and Collagen3 proteins were proliferated massively and distributed in alveolar septum extensively. The other distributions were basically the same as control group but stronger than in control group. In conclusion， Collagen1 and Collagen3 play important roles in yak pulmonary fibrosis.

In order to explore the changes of root morphological distribution， nutrient accumulation and yield under different root configuration maize varieties intercropping， monoculture and intercropping treatments were conducted both in the field and pot-cultivation to study the variation characteristics of intercropping of maize （Zea mays L.） on root traits， spatial distribution， nutrient accumulation and grain yield， two maize varieties JS501 （small root angle type） and LY16 （large root angle type） with different root system architecture were used as experimental materials. The results showed that the total root length， total root surface area， total root volume and root diameter of maize population under intercropping treatments increased by 10.19%， 19.55% and 15.95% on average compared with monoculture treatments， respectively. But there was no significant change in root diameter between intercropping and monoculture treatment. In 0~20 cm soil layer， the total root length， total surface area and total volume of maize in intercropping were 15.27%， 21.82% and 9.44% higher than those in monoculture， and 12.95%， 9.18% and 20.31% higher than monoculture at 20~40 cm， respectively. Intercropping enlarged the horizontal distribution of JS501 root and extends outward by 5 cm， deepened root vertical distribution by 10 cm in intercropping treatments and increased root length density by 26.03% on average in 40~60 cm soil layer. Intercropping also significantly improved root activities by 27.83% compared with monoculture. The accumulation of nitrogen， phosphorus and potassium in intercropping population increased by 18.27%， 14.79% and 15.75% on average compared with monoculture， respectively. Land equivalent ratio was more than 1 under intercropping and dry matter weight and grain yield were increased significantly by 11.03% and 15.36% on average compared with monoculture， respectively. Path analysis showed that total root surface areas significantly affected the accumulation of N and K， which indirectly affected dry matter accumulation and 100-grain weight， and significantly increased grain yield under intercropping conditions. However， the correlation coefficient between factors in monoculture was lower than that in intercropping. In summary， intercropping changed the spatial distribution of maize roots with different root architecture and increased the proportion of roots in deep soil. It reshaped root architecture in 40~60 cm soil layer， improved root activities and make use of the root spatial complementary. These characteristics promoted the nutrient accumulation and increased grain yield. This study provided a theoretical and practical strategy for high efficiency of nutrient resources and sustainable agriculture.

Phosphorus deficiency in the soil is a key factor limiting the growth and development of rice （Oryza sativa L.）. It is of great significance to elucidate the morph-physiological changes of rice in response to low phosphorus stress and further understand the mechanism underlying the phosphorus uptake and transport， which is also crucial to alleviate phosphorus stress on rice yield and quality. This paper mainly reviewed the changes in the morphology of roots and shoots as well as the physiological and molecular mechanisms of phosphorus uptake and utilization of rice under low phosphorus stress， and proposed crop management practices to enhance phosphorus uptake and utilization in rice. The key points for future researches were also discussed， that is， effect of interaction between rice roots and soil on the release of soil organic phosphorus， regulation and mechanism of plant hormones， especially new plant hormones， on phosphorus absorption， transport and distribution in rice plants， and development of rice varieties with high phosphorus utilization efficiency and exploring cultivation techniques to improve phosphorus use efficiency. This review is expected to provide theoretical guidance for screening and breeding rice varieties with tolerance to low phosphorus stress （phosphorus efficient varieties） and the cultivation regulation for improving phosphorus utilization efficiency.

Temperature is an important environmental factor that affects the growth, development and geographical distribution of peach trees. In order to analyze the cold resistance mechanism of Dingjiaba and explore the key genes for cold resistance, leaves of low-temperature tolerant peach Dingjiaba and sensitive peach Kanoiwa were selected as experimental materials, compared and analyzed the physiological and biochemical changes and transcripts of leaves treated at 4℃ for 2, 6 and 12 h. The results showed that the electrolyte permeability and malondialdehyde content of the two cultivars’ leaves increased gradually with the extension of cold induction time, and increased sharply at 6 h. At the same time, osmoregulation substances also gradually increased with the increasing of treatment time, such as soluble sugar, soluble protein and proline, especially in Dingjiaba. Transcriptome analysis showed that 569 and 505 differential genes were identified in Dingjiaba and Kanoiwa under cold treatment, respectively. The 569 differential genes identified in Dingjiaba were significantly enriched in plant pathogen interaction, MAPK signal pathway, sesquiterpene and triterpene biosynthesis and other metabolic pathways. It was found that the plant pathogen interaction, MAPK signal pathway and MPK3/6, WRKY22, WRKY24 and other related genes did play an important role in the cold-resistance mechanism of Dingjiaba. The results of this study lay a theoretical foundation for further study on cold resistance mechanism of peach, and provide candidate genes for breeding new cold-resistant peach varieties.

With global warming， drought stress has become one of the important factors restricting the safe production of tomato and other vegetable crops. The use of rootstocks from wild resources is a low-cost and efficient way to improve plant disease resistance and stress resistance. Previous studies have found that grafting GZ-01 rootstock， a native semi-wild tomato in Guizhou， can improve the drought tolerance of plants. In order to explore the molecular mechanism of GZ-01 on enhancing drought tolerance of wild tomato plants， the response of grafted tomato and self-grafted tomato plants to drought stress was compared by using semi-wild tomato rootstock GZ-01 and red fruit tomato as experimental materials， combined with morphophysiology and molecular biology. The results showed that under drought stress， when compared with the R/R of self-grafted plants， the damage of cell membranes of GZ-01/R grafted plants was significantly reduced， the antioxidant capacity， dry matter accumulation， CO₂ assimilation rate and water utilization efficiency of plants were significantly improved， the water loss rate of ex vivo leaves was significantly reduced， the lower stomatal closure ratio was significantly increased， and the expression of ABA synthesis-related genes and ABA content were significantly increased. Grafted plant GZ-01/R may affect the opening and closing of stomata， regulate leaf water loss， and improve plant water utilization by regulating the synthesis of ABA， thereby affect the response of plants to drought stress. This study lays a foundation for the development and utilization of native semi-wild tomato resources in Guizhou， and provides theoretical support for enhancing drought stress and studying molecular regulatory network pathways of stress resistance.

To utilization of soybean by-products and develop new nutritional flour products, soybean dregs sourdough was prepared using soybean dregs as raw material and Leuconostoc citreum E12 as the starter. The effects of addition amounts of soybean dregs sourdough (0%, 20%, 30% and 40%) on the fermentation activity, dynamic rheological characteristics, antioxidant activity and dietary fiber content of steamed bread dough (corresponding numbers as S0, S20, S30 and S40 respectively) were studied. Meanwhile, the sensory quality of bean dregs sourdough steamed bread (corresponding numbers as CS0, CS20, CS30 and CS40 respectively) and changes of texture and moisture content of steamed bread during storage were studied. The results showed that adding soybean dregs sourdough could reduce the elasticity and viscosity of steamed bread dough, and could also reduce the overall viscoelasticity of the steamed bread dough.The antioxidant activity and dietary fiber content of steamed bread dough increased significantly with the addition of soybean dregs sourdough. When soybean dregs sourdough was added at 40%, 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging rate and 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) diammonium salt (ABTS) free radical scavenging rate reached 15.61% and 79.59%, respectively, which increased by 5.10 percentage points and 15.02 percentage points compared with S0. The total dietary fiber content reached 3.91 g·100g^-1, which increased by 138.79% compared with S0. In addition, there was no significant difference in the specific volume and elongation of steamed bread prepared with 20% soybean dregs sourdough and CS0, but positive influences were observed in appearance, color, flavor and taste of steamed bread with the overall acceptability reached 7.8. After 5 days of storage, hardness, chewiness and gumminess of CS0 increased by 180.85%、69.62% and 98.08%, respectively, while that of CS40 increased by 76.19%, 30.88% and 33.96%, which was significantly lower than CS0. The moisture content of CS40 was always higher than that of CS0 during the storage period. The results showed that soybean dregs sourdough could slow down the aging of steamed bread. This study provides a technique support for the application of soybean dregs resources and the development of sourdough products.

Regreening is a typical physiological phenomenon of functional chloroplast re-differentiation during the development in Araceae ornamental plants， this phenomenon often occurs in the spathe of calla lily （Zantedeschia hybrida）， but the underlyingly regulatory mechanism remains unclear. In this study， in order to explore the regreening mechanism and improve the ornamental quality of calla lilies， a virus induced gene silencing （VIGS） system was established to verify the gene function of two key genes in chlorophyll biosynthesis during regreening， ZhGluTR and ZhChlH using the yellow variety Florex Gold of calla lily as the material. An integrated evaluation of sample locations and duration of infiltration in isolated spathe discs indicated that， the test group with 5 min of vacuum extraction in the middle spathe showed the latest regreening and the best silencing effect. Compared with the control， the silenced spathe disc of ZhGluTR and ZhChlH exhibited delayed regreening， the hue angle value increased slower. In addition， chlorophyll was less and carotenoids were more. The above results showed that VIGS system in this study can effectively silence the key chlorophyll synthesis genes ZhGluTR and ZhChlH in the spathe. The results of this study laid a foundation for revealing the molecular regulation mechanism of spathe regreening in calla lily in the future.

Ochratoxin A （OTA）， one of the most common mycotoxins in the human and animal diet， is a secondary metabolite produced by Aspergillus or Penicillium. The OTA compound is associated with a range of toxic effects， including hepatotoxicity， nephrotoxicity， enterotoxicity， neurotoxicity， immunotoxicity， carcinogenicity， teratogenicity and mutagenesis， posing a serious threat to the health of both humans and animals. In recent years， various omics researches have been developing rapidly. Genomics， transcriptomics and proteomics have contributed significantly to the identification of key molecular steps involved in OTA biosynthesis. Metabolomics is also widely used to evaluate the toxicity and mechanism of OTA. This paper reviews the researches of OTA in terms of genomic， transcriptomic， proteomic and metabolomic technologies， and proposes the trends and issues to be addressed in related research. The use of multi-omics technology can help to understand OTA comprehensively and provide scientific and theoretical reference for the studies of OTA on biosynthesis， toxicity mechanism and prevention and control.

In order to explore effect of heat stress at different reproductive growth stage on yield loss and quality in rice， two rice varieties， Huanghuazhan （HHZ） and Y-liangyou-1577 （YLY1577）， were used as materials to investigate the changes in plant growth， yield components and rice quality under CK （32 ℃ day /26 ℃ night） and heat stress conditions stimulated by the temperature of 38 ℃ day/32 ℃ night at booting stage and heading stage. The detailed periods included 7 d before heading （HS1）， 1-7 d after heading （HS2）， 8-14 d after heading （HS3）， 15-21 d after heading （HS4） and 22-28 d after heading （HS5）， respectively. Results showed that the growth and development of young panicles was mostly affected by heat stress at booting stage， and the percentage of filled spikelets was mostly affected by heat stress at the treatment of 1-7 d after heading， while the 1000-grain weight was at the treatment of 8-14 d after heading. The greatest yield loss of HHZ and YLY1577 was by heat stress of 1-7 d and 8-14 d after heading， respectively. Heat stress at booting stage caused little influence on rice quality. Compared with CK treatment， the rice quality was affected by heat stress at the stage of 1-28 d after heading， as shown by the increase of the chalky kernel and chalkiness in rice grain. The content of starch， amylose and gel consistency in rice was deceased by heat stress， and content of protein， glucose and fructose was increased by heat stress. Heat stress affected the starch RVA characteristics as shown by the increase of final viscosity， set back and gelatinization temperature and decrease of break down. Rice appearance and eating quality was mostly affected by heat stress at the stage of 8-14 d after heading， moderately by heat stress at the stage of 15-21 d and 1-7 d after heading. Taken together， the heat stress at booting stage suppressed yield formation mainly by inhibiting the growth and development of young panicle. One to fourteen days after heading was the vital stage of yield formation in response to heat stress in rice， and heat stress inhibited yield formation mainly by decreasing the percentage of filled spikelets and 1000-grain weight in this period. Eight to twenty-one days after heading was the most sensitive stage of rice quality response to heat stress， while heat stress at the stage of 8-14 d after heading may cause the double loss of yield and rice quality. Results of this research could provide scientific basis for the evaluation on rice yield and quality under heat stress at different growth stages.

As one of the plant-specific gene families， NAC genes families are widely involved in growth and developmental regulation and abiotic stress response of plant. To characterize the function of tobacco gene NtabNAC087， a direct homolog of Arabidopsis AtNAC072/RD26 tapped earlier in response to drought stress. Genetically transformed strains from the common tobacco variety K326 were constructed by gene overexpression and CRISPR/CAS9 gene edit technology. Seedlings of wild-type K326 and two genetically transformed tobacco pure strains were treated with drought stress， the leaf stomatal structure was observed and the superoxide dismutase （SOD） and catalase （CAT） activities， malondialdehyde （MDA） and proline （Pro） contents and gene expression were detected. The results showed that the overexpressed lines showed stronger drought tolerance under drought stress at bud and seedling stages， while the edited lines showed drought sensitivity. Compared with the control group， the leaves of overexpressed strains had higher stomatal density and smaller pore size. The activity of SOD and CAT and the content of Pro in the overexpressed strain were significantly increased compared with the edited strain， while the content of MDA in the overexpressed strain was significantly decreased compared with the edited strain. The expression of NtabNAC087 gene showed an increasing trend and then decreased， and reached the highest level at 6 hours of treatment. The study indicated that the NtabNAC087 gene caused significant changes in the physiological structure， antioxidant enzyme activity and osmoregulatory substance content of tobacco leaves through altering gene expression or structure， which provided experimental data for subsequent studying on its molecular mechanism in the tobacco drought stress response process.

Hemerocallis is a traditional garden plant in China， which has high economic value because it can be used as both food and medicine. Although the natural distribution of Hemerocallis is the largest in china， the related research lags behind foreign countries. At present， the horticultural varieties used in China mainly rely on foreign imports， and hortiaultural varieties with our own intellectual property rights are relatively few.In this paper， the germplasm resources of domestic Hemerocallis were introduced in detail， and the breeding achievements of new Hemerocallis varieties at home and abroad were summarized from the perspectives of different breeding objectives， such as flower shape， flower aroma， flower color， flowering period， cold resistance， disease resistance， etc. The breeding achievements of new Hemerocallis varieties at flowering time and cold resistance at home were highlighted. At the same time， the new breeding technology was summarized， and the problems and prospects in the domestic Hemerocallis breeding were discussed， which aimed to provide reference for the breeding new varieties of Hemerocallis.

The subtilase (SBT) gene family is an important gene family that controls plant growth and development and responds to environmental stress. In order to understand furtherly the number, basic characteristics, evolutionary relationship of SBT gene family in cassava, the SBT gene family was identified by bioinformatics, and the function of one member of the SBT gene family was characterized. The results showed that a total of 69 SBT members were identified in cassava genome, of which Manes.18G044300 was named MeSDD1 because it is most closely related to Arabidopsis. thaliana SDD1. Of all the SBT members, twenty-two SBT members had no introns, and 69 SBT members carried five highly conserved domains. Some SBT members were tandemly located on chromosomes, and drought response elements were found in their promoters. Two homozygous lines with high expression were screened out by fluorescence quantitative PCR for the subsequent experiments. The results indicated that the relative water contents in leaves of the two transgenic line were significantly higher than that of the wild type (WT), detached leaves of the transgenic lines lost water more solwly than that of WT, and the stomatal density of transgenic lines was significantly lower than that of WT. After water-deficit treatment for 14 d, the wilting degree of transgenic lines was less than that of WT. All the results indicated that MeSDD1 could enhance the drought resistance of A. thaliana. This study will provide gene resources for drought resistance breeding of cassava, and lay a theoretical foundation for the subsequently studying on the molecular mechanism of MeSDD1-mediated drought resistance.