Wx^mp基因背景下可溶性淀粉合成酶基因SSⅡa和去分支酶基因PUL对水稻蒸煮食味品质的影响

【目的】分析在同一主效基因(Wx^mp)背景下可溶性淀粉合成酶基因SSⅡa和去分支酶基因PUL对稻米蒸煮食味品质的影响,以期为水稻品质遗传改良提供依据。【方法】选择在SSⅡa和PUL存在多态性而其他淀粉合成酶相关基因没有多态性的半糯品系宁0145和粳稻品种武运粳21进行杂交,获得F2群体与F3株系。利用分子标记,选择含有Wx^mp基因的F2单株与F3株系,将这些F2单株与F3株系分成SSⅡa^nPUL^n、SSⅡa^nPUL^w、SSⅡa^wPUL^n和SSⅡa^wPUL^w4种基因型(n和w分别表示该基因来源于宁0145和武运粳21),分析不同基因型蒸煮食味品质性状的差异,探讨同一Wxmp基因背景下不同SSⅡa和PUL等位基因对蒸煮食味品质性状的影响。【结果】不同基因型间蒸煮食味品质性状均存在显著差异,来源于武运粳21的SSⅡa^w基因和PUL^w基因分别使直链淀粉含量增加0.29%~1.00%和0.62%~1.18%,且PUL的效应大于SSⅡa,两者间存在互作效应。SSⅡa^w基因和PUL^w基因降低胶稠度和崩解值,提高了热浆黏度、冷胶黏度、消减值和回复值,对糊化温度、峰值黏度和峰值时间的作用较小。【结论】明确了Wx^mp背景下SSⅡa和PUL基因对稻米蒸煮食味品质的遗传效应,该研究结果为SSⅡa和PUL基因的分子标记辅助选择改良稻米品质提供了理论依据。

Allelic Effects on Eating and Cooking Quality of SSⅡa and PUL Genes Under Wxmp Background in Rice

【Objective】Our aim is to analyze the genetic effects of soluble starch synthase gene SSⅡa and debranching enzyme gene PUL on eating and cooking quality under the same main gene background of Wx^mp, so as to lay a theoretical basis for rice quality improvement. 【Method】In this study, a semi-glutinous rice line Ning 0145 and japonica rice variety Wuyunjing 21 were crossed to obtain F₂ population and F₃ lines. There was polymorphism in soluble starch synthase gene SSⅡa and debranching enzyme gene PUL but no polymorphism in other starch synthase related genes between the two parents. With molecular markers, some F₂ plants and F₃ lines containing Wx^mp gene were selected and divided into four genotypes, SSⅡaⁿPULⁿ, SSⅡaⁿPUL^w, SSⅡa^wPULⁿand SSⅡa^wPUL^w(ⁿ and ^w indicated that the genes were contributed by Ning 0145 and Wuyunjing 21, respectively). The allelic effects of SSⅡa and PUL genes on eating and cooking quality under the same Wx^mp gene background was investigated by analyzing the eating and cooking quality and its differences among different genotypes. 【Result】There were significant differences for eating and cooking quality among genotypes of different parental origins. The allelic gene SSⅡa^w and PUL^w from Wuyunjing 21 increased amylose content by 0.29%-1.00% and 0.62%-1.18% respectively, and the effect of PUL was greater than that of SSⅡa. There was interaction between SSⅡa and PUL genes. The SSⅡa^w and PUL^w genes also decreased gel consistency and breakdown viscosity, increased hot paste viscosity, cool paste viscosity, setback viscosity and consistency viscosity, but had little effect on gelatinization temperature, peak viscosity and peak time. 【Conclusion】The genetic effects of SSⅡa and PUL genes on cooking and eating quality of rice under the background of Wx^mp gene were clarified. The results lay a theoretical basis for improving rice quality by molecular marker-assisted selection of SSⅡa and PUL genes.