【作者】 陈志雄；

【导师】 梁康迳；

【作者基本信息】 福建农林大学 ， 作物遗传育种， 2002， 硕士

【摘要】 选用9个不同类型的水稻品种（系），按部分双列杂交设计（6×5）配成两套亲本和F₁2个世代的供试材料。采用数量性状的加性-显性遗传模型、发育遗传模型分析了水稻谷粒重在不同发育时期的两季资料，估算水稻谷粒重某一发育时间（0→t）或某一特定发育时间段（t-1→t）的遗传效应。其主要结果如下： 非条件遗传方差分析发现，早季水稻谷粒重的发育动态主要受显性效应控制，加性效应基因在谷粒充实前期几乎不表达，后期虽有表达，但作用微小；晚季谷粒重充实过程受加性和显性效应的交替影响，谷粒充实早期以加性效应为主，中期以显性效应为主，后期以加性效应为主。条件遗传方差分析认为，早季谷粒充实的全过程，条件显性效应基因强烈表达，且发育全过程变化幅度较大；晚季加性和显性效应基因共同控制谷粒充实，但以加性效应为主，总遗传效应变化幅度较早季小。 遗传率分析结果表明，在谷粒充实全过程中，早、晚季狭义遗传率表现差异甚大，早季狭义遗传率估算值较小或为零，选择不易奏效；晚季狭义遗传率均达较高水平，在籽粒充实的中后期进行选择易取得好的效果。 杂种优势的动态分析表明，早季在谷粒充实的前期（3d～12d）非条件群体平均优势未达显著水平，随着发育进程的推进，群体平均优势均达正向的显著水平；晚季群体平均优势则在谷粒充实的中期（9d～18d）表现出正向的显著水平，后期（21d～30d）未达显著水平，条件杂种优势可合理解释非条件杂种优势分析的结果。 不同发育时期谷粒重与最终谷粒重的非条件遗传相关结果表明，早季加性相关系数未达显著水平，显性相关系数随着发育进程而加大；晚季加性相关系数在谷粒充实的全过程均达显著或极显著水平，而显性相关在后期（21d～30d）达极显著水平。条件相关分析结果表明，不同发育时期谷粒重与最终谷粒重的相关是有差异的，谷粒充实的后半段（15d～30d）早季以条件显性相关为主，而晚季以条件加性相关为主。 不同发育时期谷粒重之间的非条件遗传相关分析表明，早季以显性相关为主，晚季以加性相关为主，随着发育进程的推进，相关趋于密切。条件遗传相关分析发现，早季谷粒充实前期显性相关不密切，愈到后期其相关性趋于明显，晚季相邻时间段间的加性相关随着发育进程的推进愈加紧密。 亲本谷粒重不同发育时期的遗传效应分析发现，亲本粳籼89、02428、早恢89和佳和早占具有降低不同发育时期谷粒重的作用，而亲本多产稻、密阳46和R669则具有增加不同发育时期谷粒重的效果，亲本Lemont和IR66158-37则表现出较复杂的特点，依季别和组合而异。 另外，对早、晚季不同环境下谷粒重发育遗传的特征与水稻优质、高产育种和栽培的关系作了讨论。更多还原

【Abstract】 Two sets of tested materials were derived from partial diallel cross among nine different typesof selected rice varieties (lines).Based on experimental data at different developmental stages in early and late seasons, Estimations of genetic effects for rice grain weight at some developmental stages (0-t) or some special developmental periods (t-1-t) were conducted by using additive-dominant genetic model and developmental genetic model for quantitative traits.Analysis on unconditional genetic variance revealed that in early season the developmental dynamics of grain weight of rice was mainly controlled by dominant effects, and additive genes nearly expressed in the early period and expressed with little effects in the late period. In late season the entire courses of grain weight filling were affected by dominant and additive effects in turn, additive effects functioning principally in the early period, then dominant effects in the middle period and additive effects in the late period again. Analysis on conditional genetic variance indicated conditional dominant-effect genes expressed strikingly with large variation range during the entire courses of grain filling in early season. Additive- and dominant-effect genes governed grain filling commonly and the fonner acted mainly with less variation range of total genetic effects in late season,compared to that in early season.The results by heritabilities analysis found that narrow sense heritabilites during the entire courses of grain filling varied greatly between early and late season. The estimated narrow sense heritabilities remained little or zero in early season so that the selection for grain weight became unliable to be effective. The estimated narrow sense heritabilities all remained high level in late season, making the selection conducted in middle-late period liable to gain good result.Kinetic analysis on heterosis for grain weight at different developmental stages indicated that unconditional heterosis over mid-parent value based on population mean did not appear significant at 5% level in the early period(3d~12d) and turned positively significant as the developmental process proceeded inearly season. Unconditional heterosis over mid-parent value based on )x>pulation mean appeared positively significant in the middle period (9d~18d) of grain filling and became unsignificant in the late period(21d~30d) in late season. The result of analysis on unconditional heterosis could be interpreted rationally by conditional heterosis.The unconditional genetic relation between grain weight at different stages and final grain weight pointed out that additive relation coefficients did not reach significant level and dominant relation coefficient tended to increase as developmental process proceeded in early season. Additive relation coefficient all . reached significant or the most significant level during the entire courses of grain filling and dominant relation coefficient attained the most significant level only in the late period (21d~30d) in late season. Analysis on conditional genetic relation showed that there existed difference in the relation between grain weight at different stages and final grain weight between early and late seasons. During the latter half courses of grain filling, the relation was mainly controlled by dominant-eifect genes in early season and by additive-effect genes in late season.Analysis on unconditional genetic relation among grain weights at different developmental stages indicated that the relation was governed mainly by dominant-effect genes in early season and the relation in late season was controlled by additive-effect genes with a trend to become closer as the developmental process proceeded. The results by analysis on conditional genetic relation among grain weight at different stages found that dominant relation did not appear close in the early period of grain filling and turned more significant as late stages approached in early season. Additive relation between two adjoining stages became closer as the d更多还原