Gao Ju, Gao Lijun, Chen Weiwei, Huang Juan, Qing Dongjin, Pan Yinghua, Ma Chonglie, Wu Hao, Zhou Weiyong, Li Jingcheng, Yang Xinghai, Dai Gaoxing, Deng Guofu
Guangxi Crop Genetic Improvement and Biotechnology Laboratory, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, 530007, China.
Rice Research Institute, Guangxi Key Laboratory of Rice Genetics and Breeding, Guangxi Academy of Agricultural Sciences, Nanning, Guangxi, 530007, China.
Rice (N Y). 2024 Jun 14;17(1):39. doi: 10.1186/s12284-024-00719-7.
Improving rice quality remains a crucial breeding objective, second only to enhancing yield, yet progress in quality improvement lags behind yield. The high temperature and ripening conditions in Southern China often result in poor rice quality, impacting hybrid rice production and utilization. Therefore, to address this challenge, analyzing the molecular basis of high-quality traits is essential for molecular design breeding of high-quality hybrid rice varieties. In this study, we investigated the molecular basis of grain shape, amylose content, gel consistency, gelatinization temperature, and aroma, which influence rice quality. We discovered that quality related alleles gs3, GW7, gw8, chalk5, Wx, ALK, and fgr can enhance rice quality when applied in breeding programs. Polymerization of gs3, GW7, gw8, and chalk5 genes improves rice appearance quality. The gs3 and GW7 allele polymerization increasing the grain's length-width ratio, adding the aggregation of gw8 allele can further reducing grain width. The chalk5 gene regulates low chalkiness, but low correlation to chalkiness was exhibited with grain widths below 2.0 mm, with minimal differences between Chalk5 and chalk5 alleles. Enhancing rice cooking and eating quality is achieved through Wx and ALK gene polymerization, while introducing the fgr(E7) gene significantly improved rice aroma. Using molecular marker-assisted technology, we aggregated these genes to develop a batch of indica hybrid rice parents with improved rice quality are obtained. Cross-combining these enhanced parents can generate new, high-quality hybrid rice varieties suitable for cultivation in Southern China. Therefore, our findings contribute to a molecular breeding model for grain quality improvement in high-quality indica hybrid rice. This study, along with others, highlights the potential of molecular design breeding for enhancing complex traits, particularly rice grain quality.
提高稻米品质仍然是一项至关重要的育种目标，仅次于提高产量，但品质改良的进展落后于产量。中国南方的高温和成熟条件常常导致稻米品质不佳，影响杂交水稻的生产和利用。因此，为应对这一挑战，分析优质性状的分子基础对于优质杂交水稻品种的分子设计育种至关重要。在本研究中，我们调查了影响稻米品质的粒形、直链淀粉含量、胶稠度、糊化温度和香味的分子基础。我们发现，与品质相关的等位基因gs3、GW7、gw8、chalk5、Wx、ALK和fgr在应用于育种计划时可以提高稻米品质。gs3、GW7、gw8和chalk5基因的聚合改善了稻米外观品质。gs3和GW7等位基因聚合增加了籽粒长宽比，加入gw8等位基因的聚合可进一步减小籽粒宽度。chalk5基因调控低垩白度，但当籽粒宽度低于2.0毫米时，与垩白度的相关性较低，Chalk5和chalk5等位基因之间差异最小。通过Wx和ALK基因聚合提高了稻米蒸煮和食用品质，而导入fgr(E7)基因显著改善了稻米香味。利用分子标记辅助技术，我们聚合了这些基因，获得了一批稻米品质得到改良的确籼型杂交水稻亲本。将这些改良亲本进行杂交组合，可以培育出适合在中国南方种植的新型优质杂交水稻品种。因此，我们的研究结果有助于建立一个优质籼型杂交水稻籽粒品质改良的分子育种模型。本研究以及其他研究突出了分子设计育种在增强复杂性状，特别是稻米籽粒品质方面的潜力。
