【作者】 张小明；

【导师】 石春海；

【作者基本信息】 浙江大学 ， 作物遗传育种， 2004， 博士

【摘要】 选用粳稻“浙粳27”和籼稻“浙农5号”为材料，测定不同碾磨程度的稻米直链淀粉含量，以明确不同稻米精白度对直链淀粉含量的影响。选用稻米品质差异较大的7个籼型不育系（A）及相应的保持系（B）与5个粳型广亲和恢复系（R）杂交，组成7×5不完全双列杂交组合。测定了亲本、F₁和F₂这3个世代在不同环境中5个稻米发育时期的直链淀粉含量、胶稠度以及蛋白质和赖氨酸、蛋氨酸、亮氨酸、异亮氨酸、苯丙氨酸、缬氨酸、苏氨酸等7种必需氨基酸的含量。采用包括胚乳、细胞质和母体植株等不同遗传体系基因主效因及其环境互作效应在内的三倍体种子遗传模型和统计分析方法，系统地研究了上述籼粳杂交稻稻米蒸煮和营养品质性状的发育遗传规律。主要结果如下： 1．粳稻浙粳27和籼稻浙农5号的稻米直链淀粉含量随稻米碾磨时间的增加、米粒精白度的提高，有逐渐增高的趋势。说明米粒胚乳表层的直链淀粉含量较低，心部的直链淀粉含量较高。浙粳27和浙农5号稻米碾磨时的精白度每提高10％，直链淀粉含量约提高1.36和1.92％。揭示测定稻米直链淀粉含量时，试验所用的碾磨设备和碾磨程度需保持一致，以减少试验误差。 2．籼粳杂交稻稻米直链淀粉含量随着灌浆的进行而持续增加，至成熟期（开花后第35d）达到最大值。灌浆始期（开花后第7d）和灌浆前期（开花后第14d）杂种优势不明显，从灌浆中期（开花后第21d）开始直至成熟，有一定的杂种优势。而胶稠度和蛋氨酸含量随着灌浆的进行，持续下降，杂种优势较弱。蛋白质、赖氨酸、亮氨酸、异亮氨酸、苯丙氨酸、缬氨酸和苏氨酸等含量随着灌浆的进行，逐渐增加，至灌浆后期（开花后第28d）达最大值，杂种优势明显。 3.估算稻米开花受精后至不同发育时刻品质性状累加效应的非条件方差分析结果表明，三倍体胚乳、细胞质和二倍体母体植株等不同遗传体系的遗传主效应及其环境互作效应，均会明显影响釉粳杂交稻稻米灌浆过程中的蒸煮和营养品质性状。稻米直链淀粉含量在灌浆前期和中期，胶稠度在灌浆始期、中期和后期，赖氨酸含量、亮氨酸含量、异亮氨酸含量、撷氨酸含量和苏氨酸含量等性状在灌浆后期，蛋氨酸含量和苯丙氨酸含量在灌浆后期和成熟期均以遗传主效应为主，而蛋白质含量仅在灌浆后期以遗传主效应为主。不同遗传体系的方差分析结果显示稻米直链淀粉含量、蛋氨酸含量、亮氨酸含量、异亮氨酸含量、苯丙氨酸含量、撷氨酸含量和苏氨酸含量等性状的加性效应较大，胶稠度和蛋白质含量的加性效应和母体加性效应均较大，这些性状可在常规育种的低世代开始选择。赖氨酸含量性状的显性效应明显，则宜在高世代进行选择。 4.稻米品质性状在某一特定发育时期（l一l）*t的条件方差分析结果表明，胚乳、细胞质和母体植株中控制粕粳杂交稻稻米蒸煮和营养品质性状表现的遗传效应在多数稻米发育时期均有新的表达。开花后前7d是控制稻米直链淀粉含量和胶稠度，花后8一14d是控制赖氨酸含量，花后第15一28天是控制蛋氨酸含量、亮氨酸含量、异亮氨酸含量、苯丙氨酸含量、撷氨酸含量和苏氨酸含量等性状的新增基因表达量最多的灌浆时期，也是数量基因被激活表达最为活跃的时期。不同遗传体系的条件方差分析结果显示胶稠度在灌浆始期和中期，蛋白质含量在灌浆始期、后期和成熟期，直链淀粉含量在灌浆前期、中期和成熟期，苏氨酸含量在灌浆中期，异亮氨酸含量在灌浆中期和后期，苯丙氨酸含量在灌浆后期和成熟期均以主效应条件方差为主。赖氨酸含量在5个灌浆发育时期均以环境互作条件方差为主。 5.遗传率分析结果显示直链淀粉含量在灌浆前期、中期和成熟期，胶稠度在灌浆始期、中期和后期，撷氨酸含量在灌浆始期和后期，蛋白质含量在灌浆中期和后期，赖氨酸含量、亮氨酸含量、异亮氨酸含量和苏氨酸含量等性状在灌浆后期，蛋氨酸含量和苯丙氨酸含量在灌浆后期和成熟期的普通狭义遗传率较大，其它灌浆时期以环境互作遗传率为主。成熟期，包括互作遗传率在内的总狭义遗传率大小次序依次为稻米直链淀粉含量、亮氨酸含量、蛋白质含量、异亮氨酸含量、苏氨酸含量、苯丙苏氨酸含量、撷氨酸含量、蛋氨酸含量、胶稠度和赖氨酸含量性状。赖氨酸含量的基因显性效应最明显，遗传率明显低于其它品质性状。 6.不同亲本在灌浆发育过程中所表现出的遗传主效应和环境互作效应预测值在不同环境间存在着明显的差异。多数不育系在各灌浆时期的遗传效应预测值为正值，而多数恢复系的预钡g值为负值。应用预测值为正值的亲本，有利于增加釉粳杂交稻稻米该性状的表现，而应用预测值为负值的亲本，将降低杂种后代该性状的表现。同一亲本在各灌浆时期有不同的遗传效应，仅依靠稻米成熟期的性状表现进行亲本效应的遗传分析，不能揭示亲本在整个稻米灌浆过程中各个时期基因的遗传效应差异。 7.不同发育时期之间稻米品质性状的相关性分析结果显示直链淀粉含量、蛋白质含量和苯丙氨酸含量等性状在各灌浆发育时期之间存在着一定的正相关性。胶稠度除灌浆开始后的前几个发育时期之间，赖氨更多还原

【Abstract】 We examined the effect of degree of milling on the amylose content of the grain using a japonica rice variety, ’Zhejing 27’, and an indica rice variety, ’Zhenong 5’. In a further study seven indica male sterile lines (A) were crossed with 5 japonica restorer lines (R). Seed of 35 F1S (A×R), the parents and F2 generations were collected at 7, 14, 21, 28 and 35d after flowering. Grain quality traits analyzed were amylose content (AC), gel consistency (GC), protein content (PC), lysine (Lys) content, methionine (Met) content, leucine (Leu) content, isoleucine content (Ile), phenylalanine (Phe) content, valine (Val) content and threonine (Thr) content. Two models for developmental genetics and their corresponding statistical approaches for quantitative traits of triploid endosperm in cereal crops were used for the analysis. The first was the unconditional genetic model, which refers to the analysis of cumulative measurements along the developmental stages, while the second was the conditional genetic model, which refers to the analysis throughout the developmental stages. The main results were as follows:1. The amylose content increased by 1.36% in the japonica rice variety "Zhejing 27" and 1.92% in the indica rice variety "Zhenong 5" as degree of milling increased by 10%. Both the japonica and the indica rice variety showed the same response of AC to degree of milling. Furthermore, to minimize error in measuring AC, the need for grain samples to have the same degree of milling and grinding was highlighted.2. AC gradually increased during grain filling in indica-japonica hybrid riceand reached its highest value at the ripe stage (35d after flowering). Hybridities of F1S were not obvious at the initial filling stage (7d after flowering) and early filling stage (14d after flowering), but some hybridities from the middle filling stage (21d after flowering) onwards until ripe stage. In contrast, GC and Met content gradually decreased with grain filling and reached their lowest value at the mature stage. The content of the proteins, Lys, Leu, Ile, Phe, Val and Thr increased as grain filling proceeded and these traits reached their highest values at the late filling stage (28d after flowering), and their hybridities of F1S were greatest.3.Unconditional variance analyses showed that all the cooking quality and nutrient quality traits were simultaneously governed by triploid endosperm effect, cytoplasm effect, diploid maternal plant effect and their genotype x environmental (GE) interaction effects. AC at the early- and middle-filling stages, GC at the initial-, middle- and late-filling stages, contents of Lys, Leu, Ile, Val and Thr at the late filling stage, and contents of Met and Phe at the late- and ripe-stage were mainly governed by genetic main effects, while protein contents were mainly controlled by genetic main effects at the late filling stage. Genetic analyses showed that these traits, including AC, Met content, Leu content, Ile content, Phe content, Val content and Thr content, were mainly governed by endosperm additive effect, while GC and protein content were governed by endosperm additive effect and maternal additive effect. All these traits could be selected in earlier generation(s) in rice breeding programs. There was significant dominance effect for Lys content, and therefore it should be selected in later generation(s).4. Conditional variance analyses showed that there was new gene expression in conditional endosperm, cytoplasmic and maternal plants for cooking and nutrient quality traits. Most new gene expression was found at the initial filling stage (0-7d after following) for AC and GC, early filling stage (8-14d after following) for Lyscontent, middle- and late-filling stage (15-28d after following) for Met content, Leu content, Ile content, Phe content, Val content and Thr content, and the greatest number of genes were activated during these stages. Conditional genetic system analyses showed conditional main effect governed GC at initial- and mid更多还原