水稻籽粒灌浆速率基因GFR1的图位克隆及优异等位变异在自然群体中的发掘

发布时间：2018-05-11 23:02

本文选题：水稻 + 籽粒灌浆速率　；参考：《南京农业大学》2016年博士论文

【摘要】：水稻是重要的粮食作物,随着耕地面积的减少和人口的增加,提高水稻产量成为解决粮食安全问题的必由之路,而杂交水稻的发展为水稻单产的提高作出了重要的贡献。但迄今为止,我国的杂交水稻种植中主要以杂交稻为主,其种植面积已达到籼稻种植面积的70%左右。相比之下,杂交粳稻种植面积只占到粳稻种植面积的5%左右,两者巨大的差距给杂交粳稻的发展带来很大空间。水稻籽粒灌浆充实度是影响粒重从而直接影响稻谷产量的重要性状。大穗是F1代杂交水稻的主要优势之一,而大穗型杂交稻尤其是大穗型杂交粳稻常常表现为籽粒灌浆不足,充实度不好,不仅达不到已有颖花数应当达到的产量,而且使整精米率下降,不能充分实现大穗型品种的增产潜力和商品价值。因此,研究和探明控制水稻籽粒灌浆速率的遗传基础和作用机理,对于确定水稻高产优质高效育种策略具有重要意义。本研究围绕上述科学问题进行了两项研究,获得的主要结果分述如下。1. 水稻籽粒灌浆速率基因GFR1的图位克隆本实验室之前的研究利用两个粳稻品种稽稻和C堡构建的回交重组自交系群体(BC1F6)检测到一个控制籽粒灌浆速率的主效QTL qGFR10(本研究命名为GFR1)。为了研究GFR1在籽粒灌浆中的遗传效应,我们从构建的染色体片段置换系中分离出一个以C堡为背景,含有z^稻等位基因GFR1的近等基因系(NIL-qqgf1)。与C堡相比,NIL-gfr1的灌浆速率在灌浆前期显著高于C堡。两者在抽穗期、单株有效穗数、穗长、单穗总粒数和单穗实粒数上没有显著差异。NIL-gfr1在结实率、籽粒充实度、千粒重及小区产量上均显著的高于C堡,这表明NIL-gfr1灌浆速率的提高有助于水稻产量的提高。我们利用NIL-gfr1和C堡构建的次级F2群体进行GFR1的精细定位。遗传分析表明GFR1是一个单孟德尔因子。利用NIL-gfr1/C堡F2群体中灌浆速率快的1614个单株,我们将GFR1定位到10号染色体长臂末端34Kb的区间内。在此区间有4个预测的开放阅读框(ORFs),通过测序对比发现,ORF1(IOC_Os10g36400)的z^稻等位基因(GFR1-I)和C堡的等位基因(GFR1-c)的编码序列中检测到1个单核苷酸多态性(SNPs)位点和3个连续碱基的缺失。这些差异导致z^稻等位基因编码的氨基酸序列中缬氨酸到丙氨酸的改变和一个丙氨酸的缺失。通过转基因互补验证和转基因过表达验证我们证明了 ORF1就是GFR1。我们利用C堡和NIL-gf1与两个不同的粳稻不育系9522A和徐2A进行了配组,来评价GFR1在杂交粳稻育种中的利用价值。结果发现近等基因系与不育系的配组在籽粒灌浆速率、充实度和小区产量上均高于对照C堡与不育系组合。因此,通过分子标记辅助选择,将稽稻等位基因导入广泛应用的不育系中,可以改善杂交粳稻亲本的籽粒灌浆速率从而提高杂交粳稻的产量。2.水稻籽粒灌浆速率优异等位变异在自然群体中的发掘选用263个SSR标记对由58个地方品种和37个推广品种构成的核心种质群体进行基因型鉴定,并于2011年和2012年调查该群体5个时期(开花后7天、14天、21天、28天和35天)的籽粒灌浆速率。在95个水稻核心种质构成的群体中,5个籽粒灌浆时期水稻籽粒灌浆速率的表型变异很大,变异系数变幅为36.49%到118.26%,广义遗传率为87.5%到96.8%。群体结构分析表明,该核心种质群体被划分为7个亚群。连锁不平衡分析显示,地方品种和推广品种LD衰减(D'0.5)所延伸的最小距离分别是84.8 cM和60.3 cM,这表明地方品种LD衰减速度较推广品种慢。两年共检测到与5个灌浆期籽粒灌浆速率相关的标记24个,分布于水稻的1、2、3、4、5、6、8、9、11和12号染色体上。5个不同灌浆期检测到的标记分别为12、8、2、5和4,其中7个标记(RM480,RM5818,RM525,RM6361,RM6314,RM224 和RM72)与两个时期籽粒灌浆速率相关。其中,贡献率最高的标记位点是位于6号染色体的RM528,该标记与籽粒灌浆速率的14DAF时期显著关联,在2011年和2012年的贡献率分别为25.87%和27.19%。预测了 15组优异亲本组合,其中最优组合'南农粳62401×老来红'在整个灌浆期理论上可以使灌浆速率提高4.086 mg grain-1d-1。这些有利等位变异的载体品种可用作水稻籽粒灌浆速率遗传改良的亲本,通过聚合育种来提高水稻籽粒灌浆速率。
[Abstract]:Rice is an important grain crop. With the reduction of cultivated land and the increase of population, the increase of rice yield is the only way to solve the problem of grain security. The development of hybrid rice has made important contributions to the improvement of rice yield. The product has reached about 70% of the cultivated area of indica rice. In contrast, the area of hybrid japonica rice planting area is only about 5% of the area of Japonica rice. The huge gap between them has brought great space to the development of hybrid japonica rice. The grain filling enrichment of rice is an important trait that affects grain weight directly. The large spike is the F1 generation hybrid rice. One of the main advantages of large spike type hybrid rice, especially large panicle type japonica hybrid rice, is often characterized by insufficient grain filling and poor filling, not only can not reach the yield that the number of spikelets should be reached, but also reduces the whole precision of rice and can not fully realize the potential of increasing yield and commodity value of large spikelet type. The genetic basis and mechanism of grain filling rate of rice are of great significance for determining the breeding strategy of high yield and high quality and high efficiency in rice. Two studies have been carried out around the above scientific problems. The main results are divided into two studies before the study of the.1. rice grain filling rate gene GFR1. The main effect QTL qGFR10 controlling grain filling rate was detected by the backcross recombined inbred population (BC1F6) constructed by japonica rice varieties and C Fort (this study was named GFR1). In order to study the genetic effect of GFR1 in grain filling, we isolated a C fort from the constructed chromosome fragment replacement line and contained z^ rice equipotential group. The near isogenic line (NIL-qqgf1) of GFR1. Compared with C fort, the grain filling rate of NIL-gfr1 was significantly higher than that of C fort at the early stage of filling. There was no significant difference between the number of effective panicles per plant, the length of panicle, the number of single spike and the number of single spikes in the heading stage, which was significantly higher than that in the seed setting rate, the grain filling degree, the 1000 grain weight and the plot yield of C fort, which was significantly higher than that of the C fort. The improvement of the grain filling rate of the Ming NIL-gfr1 is helpful to the increase of rice yield. We use the secondary F2 group constructed by NIL-gfr1 and C to carry out the fine location of GFR1. Genetic analysis shows that GFR1 is a Dan Mendel factor. Using the 1614 single strains of fast filling rate in the NIL-gfr1/C Fort F2 population, we locate GFR1 to the end of the long arm of chromosome 10. In the interval of 34Kb, there are 4 predicted open reading frames (ORFs). By sequencing, we found that 1 single nucleotide polymorphisms (SNPs) sites and 3 continuous bases were detected in the encoding sequence of the z^ rice allele (GFR1-I) and C Fort (GFR1-c) in the encoding sequence of the z^ (GFR1-I) and C Fort (GFR1-c). These differences lead to the z^ rice allele. The change of valine to alanine in the encoded amino acid sequence and a deletion of alanine. We proved that ORF1 is GFR1. by transgenic complementary verification and transgene overexpression. We used C fort and NIL-gf1 to match two different japonica rice sterile lines 9522A and Xu 2A to evaluate GFR1 in hybrid japonica rice breeding. The results showed that the combination of the near isogenic line and the sterile line was higher than the control C fort and the sterile line in the grain filling rate, the filling degree and the plot yield. Therefore, the grain filling rate of the hybrid japonica rice parent could be improved by introducing the molecular marker assisted selection and introducing the rice allele into the widely used sterile lines. Increase the yield of hybrid japonica rice,.2. rice grain filling rate excellent allele variation in natural populations, selected 263 SSR markers to identify the core germplasm group composed of 58 local varieties and 37 generalizations, and investigated the population in 5 periods in 2011 and 2012 (7 days after flowering, 14 days, 21 days, 28 days and 35). The grain filling rate of 95 Rice Core Germplasms, the phenotypic variation of grain filling rate of rice at the 5 grain filling period was very large, the variation coefficient changed from 36.49% to 118.26%, and the generalized genetic rate of 87.5% to 96.8%. population structure analysis showed that the core germplasm population was divided into 7 subgroups. The minimum distance extended by LD attenuation (D'0.5) of local varieties and extended varieties was 84.8 cM and 60.3 cM respectively, which showed that the attenuation rate of LD in local varieties was slower than that of popularized varieties. In two years, 24 markers related to grain filling rate of 5 grain filling periods were detected, and they were distributed on the 1,2,3,4,5,6,8,9,11 and 12 chromosomes of rice by.5 different irrigation. The markers detected at the pulping period were 12,8,2,5 and 4, of which 7 markers (RM480, RM5818, RM525, RM6361, RM6314, RM224 and RM72) were related to the grain filling rate at two periods. Among them, the highest contribution rate was at the RM528 on chromosome 6, which was significantly associated with the 14DAF period of grain filling rate, in 2011 and 2012. The contribution rate was 25.87% and 27.19%. respectively. The best combination of 15 groups was predicted. The best combination of 'Nong Nong japonica 62401 x old red' could increase the grain filling rate by 4.086 mg grain-1d-1. in the whole grain filling period. To improve the grain filling rate of rice.

【学位授予单位】：南京农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S511;Q943.2

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