利用7射线和EMs溶液诱变处理籼稻“93lJ”种子，经过M：筛选和M,重复鉴定，分别获得465份和210份（共675份）叶、茎、穗和根等性状变异的突变体，突变频率为5．62％。7射线诱变群体的变异范围要大于EMs诱变群体，突变频率也较高，但紫色叶鞘和叶片类病斑等少数突变类型只在EMS诱变群体中出现。新构建的突变体库将有助于进一步开展水稻功能基因的研究。

Investigations to identify quantitative trait loci (QTLs) governing cooking quality traits including amylose content, gel consistency and elatinization temperature (expressed by the alkali spread value) were conducted using a set of 241 RIL populations derived from an elite hybrid cross of "Zhenshan 97" 9 "Minghui 63" and their reciprocal backcrosses BC1F1 and BC2F1 populations in two environments. QTLs and QTL 9 environment interactions were analyzed by using the genetic model with endosperm and maternal effects and environmental interaction effects on quantitative traits of seed in cereal crops. The results suggested that a total of seven QTLs were associated with cooking quality of rice, which were subsequently mapped to chromosomes 1, 4 and 6. Six of these QTLs were also found to have environmental interaction effects.

The analysis of temporal patterns of genetic effects for thousand-seed weight (TSW) and oil content (OC) in rapeseed was conducted at five different seed development times using unconditional and conditional genetic models for diploid seed quantitative traits. Phenotypic means among generations and seed development times in 2 different years revealed considerable variation for both TSW and OC. The expression of genes from diploid embryo, cytoplasmic and maternal plant genetic systems were all found to be important for the F1 generation, with maternal effects playing a more prominent role for both traits at most times. The conditional analysis indicated that the stage-specific gene expression from the maternal plant was influenced by environment. Higher magnitudes of additive and cytoplasmic effects were observed for both traits. Narrow-sense heritability was high for both traits at all developmental times with maternal heritability being more prominent at most times. Genetic correlations between TSW and OC were mostly negative over developmental times.

The floral organs are formed from floral meristem with a regular initiation pattern in angiosperm species. Flowers of naked seed rice (nsr) were characterized by the overdeveloped lemma and palea, the transformation of lodicules to palea-/lemma-like organs, the decreased number of stamens and occasionally extra pistils. Some nsr spikelets contained additional floral organs of four whorls and/or abnormal internal florets. The floral primordium of nsr spikelet is differentiated under an irregular pattern and an incomplete determination. And molecular analysis indicated that nsr was a novel homeotic mutation in OsMADS1, suggesting that OsMADS1 played a distinct role in regulating the differentiation pattern of floral primordium and in conferring the determination of flower meristem. The gain-of-function of OsMADS1 transgenic lines presented the transformation of outer glumes to lemma-/ palea-like organs and no changes in length of lemma and palea, but loss-of-function of OsMADS1 transgenic lines displayed the overdeveloped lemma and palea. Both findings revealed that OsMADS1 played a role in specifying lemma and palea and acted as a repressor of overdevelopment of lemma and palea. Moreover, it was indicated that OsMADS1 upregulated the transcript level of AP3 homologue OsMADS16, using real-time PCR analysis on gain- and loss-of-function of Os- MADS1 transgenic lines.

Using a newly developed mapping model with endosperm and maternal main effects and QTL environment interaction effects on quantitative quality traits of seed in cereal crops, the investigation of quantitative trait loci (QTLs) located on triploid endosperm and diploid maternal plant genomes for protein content and lysine content of rice grain under different environments was carried out with two backcross (BC1F1 and BC2F1) populations from a set of 241 recombinant inbred lines derived from an elite hybrid cross of Shanyou 63. The results showed a total of 18 QTLs to be associated with these two quality traits of rice, which were subsequently mapped on chromosomes 2, 3, 5, 6, 7, 10, 11 and 12. Three of these QTLs were also found havingQTL environment interaction effects. Therefore, the genetic main effects from QTLs located on chromosomes in endosperm and maternal plant genomes and their QTL environment interaction effects in different environments were all important for protein and lysine contents in rice. The influence of environmental factors on the expression of some QTLs located in different genetic systems could not be ignored for both nutrient quality traits.