论文部分内容阅读
落粒性是水稻非常重要的农艺性状,适度落粒有利于减少产量损失和水稻机械化收割,提高生产效率.因此鉴定落粒基因对水稻生产具有重要意义.本研究以日本晴为受体亲本、优良恢复系R225为供体亲本,采用高代回交和SSR标记辅助选择相结合的方法,鉴定了一个携带易落粒主效单基因的水稻染色体片段代换系Z481.Z481含有4个染色体代换片段,位于第1,3,6染色体上,其代换片段长度分别为8.30,6.17,3.12和10.79 Mb,平均为7.10 Mb.与受体日本晴相比,Z481的株高、穗长、倒一节间长、倒二叶宽显著降低,剑叶宽和结实率显著增加,其他重要农艺性状如叶长、有效穗数、每穗粒数和千粒重均无显著差异.扫描电子显微镜观察表明Z481的护颖和枝梗之间的离层在成熟时期已被完全降解,而日本晴的离层完整,在细胞学上解释了Z481易落粒性产生的原因.进一步利用日本晴与Z481杂交产生的F_1和F_2群体对易落粒基因进行了遗传分析和分子定位.该易落粒性状受单基因隐性调控,最终将该基因定位于第6染色体RM253和ZTQ53之间824 kb的区域,暂命名为SH6(t).目前,在第6染色体尚无落粒基因克隆的报道.由于染色体片段代换系除代换片段外与受体亲本的遗传背景一致,且Z481易落粒遗传行为简单,基本未携带育种不利性状.因此,本研究无论对SH6(t)的克隆,还是进行基因聚合育种培育适度落粒新品种均具有重大利用价值.
Grain shattering is a very important agronomic trait in rice. Appropriate grain fall is beneficial to reduce yield loss and mechanized harvesting of rice and improve production efficiency. Therefore, identification of shattering genes is of great importance to rice production.In this study, Restorer line R225 was used as the donor parent, and a combination of high backcross and SSR marker-assisted selection was used to identify a rice chromosomal segment substitution line Z481.Z481 that contained the main single-legible major single gene with four chromosomal substitutions The fragment was located on the chromosomes 1, 3 and 6 with the length of substitutional fragment of 8.30, 6.17, 3.12 and 10.79 Mb, respectively, with an average of 7.10 Mb.Compared with the receptor Nipponbare, the plant height, Internodes length and second leaf width were significantly decreased, width and seed setting rate of flag leaf were significantly increased, and other important agronomic traits such as leaf length, effective panicle number, grain number per spike and 1000-grain weight were not significantly different.With scanning electron microscopy The separation between sakura and branch stems has been completely degraded at maturity, while the separation of Nipponbare is complete, which explains cytologically the reason for the easy fall-off of Z481.Further use of the F_1 F 2 population was subjected to genetic analysis and molecular mapping of the easily shedding gene.The recessive grain trait was implicitly regulated by a single gene and the gene was finally located in the region of 824 kb between RM253 and ZTQ53 on chromosome 6 and tentatively named as SH6 (t) .At present, there are no reported clones of cloned genes on chromosome 6. Because the chromosomal segment substitution lines are consistent with the genetic background of the recipient parent except the substitution fragment, the genetic behavior of Z481 is very simple Therefore, in this study, both the cloning of SH6 (t) and the breeding of genetically modified varieties of moderately shed new varieties are of great value.