【作者】 张坚勇；

【导师】 翟虎渠；

【作者基本信息】 南京农业大学 ， 作物遗传育种， 2003， 博士

【摘要】 随着人民生活水平的提高，对优质稻米的质量和数量都提出了更高的要求，品质改良成为目前水稻育种的重要目标，也是水稻研究的热点和难点问题。当前，我国稻米品质存在的主要问题在于稻米食味品质和外观品质差(如：垩白偏高等)。本研究围绕稻米品质稳定性这一主题，从食味品质和外观品质入手，利用Asominori／IR24的染色体片段置换系(CSSLs)群体连续3年分析食味品质相关QTL的表达稳定性；同时，利用18个水稻品种在两年3点多个环境中研究水稻食味和外观品质性状的表型稳定性，期望为优质水稻品种的培育、推广应用以及品质形成的分子机理深入研究奠定基础。主要结论如下： 1．利用Asominori／IR24的CSSL群体，分析稻米蒸煮食味品质9个性状相关QTL连续3年(2000-2002年)的表达稳定性，结果发现：影响光泽度的qLT-8、控制柔软性的qTD-6和qTD-8、共同作用于综合口感的qIVVOE-6a和qIVOE-8，以及影响直链淀粉含量的qAC-8等6个QTL，在3年都能稳定地表达。这为QTL的精细定位、克隆以及优质食味品质水稻品种的辅助选择(MAS)育种都奠定基础。 2．利用加性主效应和乘积交互作用模型(AMMI模型)，分析18个供试品种20项品质指标在两年3点(2001-2002年，南京、金湖和东海)表型稳定性，结果表明：①稳定性高的品质性状有粒长、粒宽和长宽比(Di平均值≤0.36)，相反，垩白率、垩白大小、最高粘度、冷胶粘度、消减值和米饭综合口感的稳定性偏低(Di平均值＞1.1)，另外11项品质性状的稳定性适中(0.49≤Di平均值≤1.06)；②品质性状稳定性高(Di平均值＜0.8)的品种有南京16号、W002、汕优63号、3004和丰优香占；而稳定性较低(Di平均值＞1.1)的品种有常优1号、淮引9901、扬两优6号和特优559。这对优质稳定水稻品种的培育和推广利用都有重要指导意义。 3．粒长、长宽比、直链淀粉含量、糊化温度、蛋白质含量、热浆粘度、冷胶粘度、回复值和消减值9个指标都与米饭综合口感(IVOE)呈极显著负相关，而粒宽、崩解值、米饭光泽度、柔软性、粘性和弹性6个指标都与米饭综合口感呈极显著正相关。从相关程度来看，崩解值、消减值、糊化温度、蛋白质含量等理化 指标与IVOE之间的相关性，都比直链淀粉含量与WOE之间的相关性高，因 此综合利用这些理化指标，在育种早期世代选择，克服早代所获稻米不足以食 味品尝的困难，对加快优质育种进程、提高选择效率均有重要意义。4.除稻米粒长、粒宽和长宽比受栽培生产方式影响很小外，另外17个品质性状在 四种食品生产方式下都存在显著差异。单就改良米饭适口性而言，绿色食品生 产方式下最佳;对于外观品质，高产栽培方式下最好，因此在优质米产业化生 产中，应首先选择圣白低且对环境钝感的优质品种，再结合绿色食品生产技术， 以生产出外观和食味品质优良的安全无公害大米.更多还原

【Abstract】 Quality improvement of rice grains has become one of the most important goals in rice breeding. The major problems for rice grain quality are the bad appearance and eating quality in China, i.e., the high percentage of chalky grain and bad palatability of cooked rice. In this study, a chromosome segment substitution lines (CSSLs) population, derived from Asominori (japonica)/ IR24 (indicd) with Asominori as the recurrent parent, was planted and phenotyped for nine rice-eating-quality traits in three successive years. Thereby, quantitative trait loci (QTLs) for these cooking and eating quality traits were determined, meanwhile expression stability of the QTLs was investigated across the three years. On the other hand, 18 rice cultivars were selected and planted by four production ways in two years and three sites, of which 20 eating and appearance quality traits were observed and analyzed to evaluate the stability of the cultivars and traits with additive main effects and multiplicative interaction (AMMI) model. The main results are as follows:1. A total of 32 QTLs for nine cooking and eating quality traits were identified in the three years, and the phenotypic values were different significantly (p<0.001) between the CSSLs harboring any of the QTLs and Asominori. Among them, six QTLs on chromosomes 6 and 8, namely qLT-8 for luster (LT), qTD-6 and qTD-8 for tenderness (TD), qIVOE-6a and qIVOE-8 for IVOE, and qAC-8 for amylose content (AC), were detected consistently across the three successive years, indicating that genes of the QTLs could function stably across different years. The markers flanking the QTLs would be very useful not only for applying marker-assisted selection (MAS) to rice breeding for quality improvement, but also for fine mapping and map-based cloning of these genes.2. Stability for the eighteen tested cultivars was analyzed based on the phenotypic values of twenty quality traits in two years and three sites with the AMMI model. Three appearance quality traits, namely, grain length (GL), grain width (GW) and length-width ratio (LWR), showed good stability in six different environments; while six quality traits low, including ratio of grains with chalkiness (RC), size of chalkinessper grain (SC), peak viscosity (PKV), cool paste viscosity (CPV), setback viscosity (SBV) and integrated value of organoleptic evaluation (IVOE) of cooked rice. Moreover, the other eleven quality traits showed medium stability. On the other hand, five cultivars, Nanjing 16, W002, Shanyou 63, 3004 and Fengyouxiangzhan, were characterized by high stability, while four low, i.e., Changyou 1, Huaiyin 9901, Yangliangyou 6 and Teyou 559. These results would be very useful to improve rice quality and production stability.3. Negative correlation were detected among IVOE and eight quality characters, namely, GL, LWR, AC, CPV, SBV, consistency viscosity (CSV), gelatinization temperature (GT) and protein content (PC); while positive among the IVOE and GW, LT, TD, viscosity (VC), elasticity (EL) and breakdown viscosity (BDV), respectively. It is noteworthy that the correlation coefficient between AC and IVOE was lower than that between IVOE and other physical-chemical properties such as BDV, SBV, GT, PC, etc. Therefore, it would be more practical to apply these physical-chemical properties related to eating quality rather than AC for improving the palatability of cooked rice.4. The four cultivations for rice could affect all the twenty quality traits significantly except GL, GW and LWR. In term of the palatability of cooked rice, the green food cultivation produced the best rice quality, however, the high production cultivation could produce the rice grains with lower RC and SC. Therefore it might be a good strategy that the rice cultivars of lower RC and higher stability could be planted by green food cultivation to produce the good-quality and safe rice grains.更多还原