概述了植物系统对重金属的吸收及去除重金属的作用；微生物对重金属的生物积累、生物转化及对重金属的抗性和解毒作用。介绍了国内外重金属污染生物修复研究结果及发展前景。

Growing tips of 11 genotypic wheats at the glume differentiation stage were cultured on MS medium. The callus induction frequency was about 100%. Plant regeneration frequency was 73.7-100% after subcultured for 120 days.Regenerated plant were planted in the field.Extensive variation was observed among 219 regenerants. Variation characters included fertility, height, heading date, spike shape, awns,grain characters, glume colour, waxiness, a-amylase and gliadin proteins.Frequencies and compositions of variation among the 11 genotypes were different.

综述了化学诱变育种的发展历程 ,分析了常用化学诱变剂EMS、NaN3和PYM的诱变机制、诱变效应及化学诱变育种的特点 ;介绍了EMS 石蜡油处理玉米成熟花粉和苯甲酰胺与EMS、PYM复合处理 2种新的诱变技术。

The fate of N fertilizer in winter wheat growth season was studied by 15 N mcro plot experiment under the conditions of conventional irrigation,adequate phosphorus and potassium supply.The results showed that the uptake of N by winter wheat sharply increased with the increase of nitrogen fertilizer rate.About 45% of total N uptake came from fertilizer N while the other 55% of total uptake from soil nitrogen at harvest.The recovery of fertilizer N in soil crop system sharply decreased with nitrogen fertilizer rate meanwhile loss rate increased respectively.When N rate is 120 kg N/ha(low N input),45 3% of fertilizer N was utilized by plant,45 3% remained in 0～100cm soil layer and only 9 4% not recovered by plant or in 0～100cm soil layer.However,when N rate was 360kgN/ha(high N input),23 2% was utilized by plant,20 9% remained in 0～100cm soil layer and 55 9% lost from plant soil system.Organic combining form was the main residual form of fertilizer N,NH 4 N form occupied a small percentage of total residual fertilizer N,and NO 3\|N form increased rapidly with N rate.Traced fertilizer N was found in all 0～20,20～40,40～60,60～80 and 80～100cm soil layers,showing the movement of fertilizer N was at least below 100cm soil depth in winter wheat growth season.

The photosynthetic rate in rice leaf was significantly inhibited by 0.025～1.0mmol/L of Cu~(2+), Cd~(2+) and Hg~(2+). With increasing of Cu~(2+), Cd~(2+) and Hg~(2+) concentration, the inhibiting degree of photosynthetic rate was enhanced. Tracer kinetic analysis indicated that, 0.5mmol/L Cu~(2+), Cd~(2+) and Hg~(2+) inhibited the transformation between starch and sugar, disturbed the translocation of photosynthates from leaves. Consequently, sugar accumulated in the leaves, which might induce a feedback-regulation of photosynthetic rate. Using polyacrylamide concentration gradient gel electrophoresis to analyze the activity of amylase isozymes indicateed that, the amylase isozymes expression in rice leaf was inhibited by 0.1～0.5mmol/L Cu~(2+), Cd~(2+) and Hg~(2+), hence, the transformation between starch and sugar was blocked.

The effects of CBF1 on cold tolerance,growth and development of low-temperature sensitive plant were investigated by delivering Arabidopsis CBF1 gene(cbf1) concatenated with GUS gene(udiA) into tobacco.The expression levels of exotic genes in transformed plant were shown by the GUS activity.The results showed that the overexpression of CBF1 could obviously improve cold tolerance of plant.Compared with non-transformed control plants,the transformed plants had a shorter and stronger stem,more leaves that were bottle-green and thicker,and a longer growth period.CBF1 overexpression also promoted the growth of axillary shoots,but had little effect on the fecundity of plants.The degree of the effects depended on the expression level CBF1.Proper regulation strategy for gene expression should be concerned when using CBF1 to modified plants.

Epidemics such as BSE,mouth and foot disease,avian influenza have brought new pressure to food safety management,constituted a extreme threat to people health,and caused serious economic loss and social scare to countries with outbreaks of above diseases.Isotopic tracing technology is an effect tool for tracing food origin and implementing the preservation of production premise in the world at present,and it is promising in the field of food safety traceability,so some developed countries have put a lot of effort on establishment of isotopic technology for food traceability.In this paper,the basic principles of isotopic tracing technology and the recent research advancement were be expounded,and the differentiate and connection was be compared between isotopic tracing technology and others.Furthermore,the suggestion about study of isotopic tracing technology in China was put forward.The aim of the paper is to promote the establishment and improvement of food traceability system,and ensure the consumer health.

The C-repeat binding factors(CBFs) are one of family of transcription factors.These proteins play an integral role in the ability of plants to cold acclimate and increase in freezing tolerance.They perform this function by binding to the CRT/DRE,a cis-acting element presents in the promoters of the cold-regulated(COR) genes and then activating COR gene expression.Here we review the structure features and functional characterization of CBF transcription factors, also we discuss its regulatory roles in plant freezing tolerance.

The effects of γ-ray irradiation on seeds and stems of ornamental lotus were studied. The results show that the mutation rate of seeds is higher than that of stems, and 30～60Gy is the appropriate irradiation dose. The varieties with red or multi-color flower are more mutable than those with white flower. Two varieties were selected.

PLM12 was a thermo\|sensitive purple leaf mutant selected from Indica rice variety Luqingzao 1 treated with pingyangmycin in combination with γ rays,and for display of its mutant character,a relatively high temperature was required.Compared with its original parent,many major agronomic traits of PLM12 changed to varied extents.Based on spikelet cutting experiment,it was believed that significant decreases in number of filled grains per panicle,fertility,and 1000\|grain weight in PLM12 resulted mainly from a great decline in photosynthetic capacity and serious lack of photosynthates in purple leaves.It was indicated by genetic analysis that expression of the mutant phenotype in PLM12 was conditioned by a single recessive major nuclear gene and modified by several minor genes.

本文介绍了小麦矮源在中国和世界范围内的利用以及主要的矮源 ,矮秆基因的来源、基因定位及遗传研究进展方面的情况 ,并对其未来发展提出自己的看法

The relationship between cellulose content of the normal mature fiber of cotton and its fiber strength had been analysied.By using 3H labelling te-chnique,the effect of cellulose deposition speed on the fiber strength had been studied.The sellulose content of normal mature fiber of all species ( varieties ) was higher than 85%,but it had no significant effect on the fiber strength.When the cellulose content was lower than 80%,the fiber strength increased with increasing cellulose content.The deposition speed of cellulose had significant effect on the fiber strength.

Technique of mutation breeding in chrysanthemum was studied by means of 60 Co γ irradiation and tissue culture.The results showed that radiosensitivity varies greatly with different varieties of chrysanthemum;the suitable doses are 2～3 krad for radical buds,cutting boughs and the whole plants,and 0 8～1 0 krad for callus from cultures in vitro .Tissue culture has an advantage over cuttage in isolation of mutant mosaics.Mutation rates of flowers of regenerated plants from in vitro culture of VM 0,VM 1,VM 2 are 66 7%,56 3%,and 38 5% respectively,all of which are higher than that from irradiated plants.Practice of breeding 14 new chrysanthemum varieties proved that by combination technique of irradiation with tissue culture, a higher breeding effeciency and shorter period of breeding was achieved.

Pingyangmycin ( PYM ) as、a mutagen was applied to crop mutational breeding in this experiment. The mutagenic effects of PYM on barley was studied by means of seed treatment. The results showed that PYM was a yery effective mutagen for plant breeding.Compared with EMS, PYM could induce higher chromosomal aberration frequency and phenotypic variation frequency of M2 generation. In early. maturing period, higher tillering capacity could be obtained in M2 generation with seeds treatment with PYM.The optimal concentration of PYM applied was 30 μg/ml.

14different qualities parents of indica hybrid rice, including 7 CMS lines and 7 restorers,were chosen to analyze the combining ability of milling property and physical property by way of p×q incomplete diallele cross (NCⅡ) design. The results showed that:①Both general combining ability(gca) and specific combining ability(sca) were highly significant in all 12 characters; the genetic additive effects was principal in brown rice length (BRL), brown rice width(BRW), ratio of length to width of brown rice(RLWBR), milled rice length (MRL), milled rice width(MRW), ratio of length to width of milled rice (RLWMR) and chalkyness(CN) ;while the nonadditive effects were greater in brown rice rate(BRR),milled rice rate (MRR), head rice rate(HRR), chalky rice percentage(CRP) and area of chalky rice (ACR).②Through the analysis of the contribution ratio of the male, female and their interaction to the total variance of the quality characters in F-1 hybrids, the results showed that BRR, MRR, BRL,MRL and ACR were influenced more greatly by restorer line than by CMS line, but the others were influenced more greatly by CMS line than by restorer line.③The gca and sca effects were independent each other, which suggests that it is essential to make widely testcrosses in the selection of hybrid combinations.There existed a positive correlation between gca and phenotypic value of parents, which indicates that great attention must be paid to the improvement of parent own characters in hybrid rice breeding. ④BRL,BRW,RLWBR,MRL,MRW and RLWMR had higher narrow heritabilities(h2 N),and these characters may be used as indirect traits in early breeding generation.

TILLING (Targeting Induced Local Lesions IN Genomes) is a novel reverse genetics technology that provides a high throughput and low cost strategy for efficient, large-scale screening of point mutations induced by chemically mutagenic agent-Ethyl Methane Sulfonic acid (EMS). In this paper, the methodology and technical advantages of TILLING were briefly introduced and its applications in plant functional genomics, mutational molecular breeding and predicting the mutation frequency were tentatively discussed.

 Correlation, cluster, principal component and discrimination analysis techniques were used to study the relationship between several morphological indexes and drought resistance of wild, semi-wild and cultivated soybean. The results showed that under drought stress, plant height, plant weight, branchy number, pods/plant, seeds/plant, 100-seeds weight and yield/plant declined in different degrees, while the nodes position of yellowing abscission leaves increased depending on the tested genotypes. Drought resistance coefficients were significantly positively correlated to plant height, plant weight under drought stress, and were significantly negatively correlated with nodes position of yellowing abscission leaves. Principal component analysis was performed to select the first three principal components and their cumulative contribution of variance accounted for 88.38%. Cluster analysis had been used to classify the drought resistance of soybean, and by means of discrimination analysis, such indexes as relative plant height, nodes position of yellowing abscission leaves, relative seeds weight, surface hairs on downer of leave blade and drought resistance coefficient were selected. 15 different soybean genotypes were classified into high resistance, medium resistance, sensitive and high sensitive groups according to these indexes. Wild and semi-wild soybean belonged to high resistance, so it is important to utilize the excellent and drought tolerant germplasm breeding the new soybean varieties.

Dry seeds of two genotypes of winter wheat ZY9 and ZH7 were irradiated by mixed high-energy particle field with different doses of 0, 109, 145, 195, 284 and 560Gy, which was generated from E2 beam lines of LINAC of Beijing Electron Positron Collider. The cytological effects on root tip cell of wheat seeds were studied with the same dosage of γ-rays irradiation as a control. The results showed that the irradiation of mixed high-energy particle field inhibited mitoses and produced various chromosomal aberrations such as micronucleus, chromosome bridges, circular chromosomes and dissociative chromosomes in root tip cells of wheat with significant dose-effects. Higher rate of cytological damages and percentage of chromosome circles and fragments were found in the mixed particle field irradiation than in γ-rays irradiation, indicating in the relative higher biological effects of irradiation of mixed high-energy particle field than those of γ-rays in the M_1 generation of wheat.

Effects of Melatonin (MT) on photosynthetic and fluorescence parameters in leaves of cucumber seedling with spraying exogenous were investigated, using cucumber variety of ‘Jinchun 4’ under high temperature stress. Results showed that net photosynthetic rate (Pn) declined sharply, but stomatal conductance (Gs), intercellular CO2 concentration (Ci) and transpiration rate (Tr) increased after treated for 24h at high temperature of 40℃±1℃. The Pn, Gs, and Tr increased at first then decreased rapidly after treated with exogenous MT, while Ci was the opposite, which suggested that Pn reduction was mainly due to non-stomatal factors. The decrease in primary conversional efficiency of light energy (Fv/Fm), electron transport rate (ETR), PSII quantum yield of electron transport (ΦPSII) and chlorophyll contents accounted for the decline of Pn through further analysis on chlorophyll fluorescence parameters. The seedlings treated with MT had higher contents of chlorophyll, Fv/Fm, ETR and ΦPSII. It was illustrated that melatonin can alleviate the heat stress on photosynthetic organ damage and improving photosynthetic capacity of cucumber seedlings.