>Rice heading date, or flowering time, is important for yield optimization and regional adaptation. While many genes controlling this trait in rice are known, breeders often need only slight adjustments. Our study used the CRISPR/Cas9 method to edit the Hd6 gene in the early-maturing, late-season japonica rice cultivar Nanjing 46 (NJ46), creating three mutants with reduced flowering times of 9-12 d under natural conditions in Nanjing city, Jiangsu Province, China. These mutants showed higher Hd3a and RFT1 expression levels without compromising yield or eating and cooking quality, demonstrating that Hd6 gene editing is an effective precision breeding tool for shortening heading date without laborious traditional methods.

Aleurone forms the outermost layer of the rice endosperm and plays a critical role in apoplastic nutrient uptake during endosperm development. Thickening the aleurone layer has been proposed to significantly increase the nutrient content of rice grains. In this study, we used a CRISPR/Cas9-mediated precise base editing method to target OsROS1,

In order to estimate the glycemic index（GI） of rice quickly and economically, the rice varieties Zijinnuo 2, Nanjing 04062 and Ningxiyou Y16 with different amylose contents were used as the research materials. The effects of sample pretreatment methods, the addition amount and method of α-amylase and amyloglucosidase on the hydrolysis characteristics of rice starch were analyzed. The suitable pretreatment method of rice starch in vitro digestion, the suitable addition amount and method of α-amylase and amyloglucosidase were determined. The GI value of rice was estimated according to the starch hydrolysis index and hydrolysis rate. The results showed that the suitable starch in vitro digestion test scheme for estimating the glycemic index of rice was as follows: 0.75 g of polished rice was boiled with water, then extruded 30 times by artificial stick, and the volume was adjusted to 15 ml with pH 6.8 phosphate buffer. Then, 1 ml 300 U/ml α-amylase and 1 ml 50 U/ml amyloglucosidase were added synchronously to hydrolyze for 60 min. By monitoring the dynamic change of glucose content in the hydrolysate, the GI value of rice could be estimated by the starch hydrolysis index within 1 h and the hydrolysis rate at 1 h. The GI estimation values of nine rice samples indicated that the experimental method established in this study could realize the preliminary screening of low GI rice resources and genetic materials.

Grain size, determined by grain length, grain width and grain thickness, is associated with grain yield and quality. Many genes controlling grain size were cloned and their related regulatory mechanisms were clearly clarified. However, whether these genes can be directly introduced into japonica rice for grain size improvement is unknown. We edited GS9,

氮素是促进水稻物质生产和产量形成的首要因素,其高效与合理的利用是农业可持续发展的重要保障.培育含有氮高效基因的水稻品种,充分发挥氮素高效吸收和利用遗传潜力是提高氮肥利用率、减少氮肥施用量的有效途径.本研究从氮素的吸收、转运、再分配和再利用等环节,选择了OsNR2、OsNPF6.1、OsTCP19、OsLHT1和OsGRF4共5个基因作为水稻氮高效遗传改良的基因组合,根据已报道的功能位点设计得到与目标基因共分离的基因功能标记,包括6对等位特异PCR标记和1对InDel标记,并对70份常规籼稻,34份常规粳稻和84份太湖资源水稻材料进行了鉴定.结果表明,OsNR2在籼稻中分布较广,OsNPF6.1、OsTCP19、OsGRF4在籼稻中分布较少,但是均未在常规粳稻中检出;常规粳稻中仅含有OsLHT1;同时我们还筛选出2份材料同时含有OsNR2、OsNPF6.1和OsGRF4高效单倍型.本研究开发的功能标记和筛选出的材料为通过分子标记辅助选择方法培育氮高效水稻新品种提供了技术支撑.

大米是典型的淀粉丰富的食物,是全世界大多数人口尤其是亚洲人口每日主要的卡路里来源.目前水稻品种大多数属高升糖指数(全称为血糖生成指数,glycemic index,GI)水稻,会诱发由于高热量摄入而致血糖失调的健康问题.已有大量研究者在探索降低大米血糖指数的方法.本文重点对稻米升糖指数的影响因素、筛选方法、遗传基础以及遗传改良等的相关研究进行总结,并对未来的研究方向提出了一些建议.