Diverse variation of reproductive barriers in three intraspecific rice crosses.
Diverse variation of reproductive barriers in three intraspecific rice crosses.
复制标题
DOI：
--
复制
发表时间：
2002
期刊：
影响因子：
3.3
通讯作者：
Y. Harushima;M. Nakagahra;M. Yano;Takuji Sasaki;N. Kurata
中科院分区：
文献类型：
--
作者：
Y. Harushima;M. Nakagahra;M. Yano;Takuji Sasaki;N. Kurata
生殖障碍被认为在物种形成和分化过程中起着重要作用。亚洲水稻栽培品种，水稻，可分为两个主要类型，粳稻和籼稻，根据几个特点。籼粳杂种的育性因杂交种而异。在不同的籼粳杂交中，许多与生殖障碍有关的基因（杂种不育基因、杂种弱势基因和配子体竞争基因）已被报道。为明确籼粳分化的状态，对日本晴/Kasalath（NK）、F11084/稻仁桥（FD）和F11007/金南当普提（FK）3个不同籼粳杂交组合F（2）群体中导致孟德尔分离比率偏离的所有生殖障碍进行了定位和比较。通过对覆盖整个基因组的DNA标记的等位基因频率进行回归分析来进行生殖障碍的定位。NK中有33个生殖障碍（15个配子体和18个合子），FD中有32个生殖障碍（15个配子体和17个合子），FK中有37个生殖障碍（19个配子体和18个合子）。三个杂交组合的生殖障碍数量相似，但大多数障碍分布在不同的位点。这些生殖障碍是在籼粳分化后形成的。考虑到粳稻和籼稻品种之间的高度遗传相似性，每个杂交组合的生殖障碍差异出乎意料地多。籼粳杂种的生殖障碍可能比其他遗传因素进化得更快。造成这些障碍如此迅速演变的一种可能的力量可能是水稻的驯化。
Reproductive barriers are thought to play an important role in the processes of speciation and differentiation. Asian rice cultivars, Oryza sativa, can be classified into two main types, Japonica and Indica, on the basis of several characteristics. The fertility of Japonica-Indica hybrids differs from one cross to another. Many genes involved in reproductive barriers (hybrid sterility, hybrid weakness, and gametophytic competition genes) have been reported in different Japonica-Indica crosses. To clarify the state of Japonica-Indica differentiation, all reproductive barriers causing deviation from Mendelian segregation ratios in F(2) populations were mapped and compared among three different Japonica-Indica crosses: Nipponbare/Kasalath (NK), Fl1084/Dao Ren Qiao (FD), and Fl1007/Kinandang puti (FK). Mapping of reproductive barriers was performed by regression analysis of allele frequencies of DNA markers covering the entire genome. Allele frequencies were explained by 33 reproductive barriers (15 gametophytic and 18 zygotic) in NK, 32 barriers (15 gametophytic and 17 zygotic) in FD, and 37 barriers (19 gametophytic and 18 zygotic) in FK. The number of reproductive barriers in the three crosses was similar; however, most of the barriers were mapped at different loci. Therefore, these reproductive barriers formed after Japonica-Indica differentiation. Considering the high genetic similarity within Japonica and Indica cultivars, the differences in the reproductive barriers of each cross were unexpectedly numerous. The reproductive barriers of Japonica-Indica hybrids likely evolved more rapidly than other genetic elements. One possible force responsible for such rapid evolution of the barriers may have been the domestication of rice.