Genetic Dissection of Tiller Number qTN4 in Rice

Tiller number (TN) is an important trait that contributes to yield in rice (Oryza sativa L.). A set of 76 chromosome segment substitution lines (CSSLs) derived from the super-hybrid cross between Zhonghui 9308 (ZH9308) and Xieqingzao B (XQZB) was used map quantitative loci (QTL) controlling tiller (TN). total four QTLs were detected Fuyang, Zhejiang Province (30.15° N, 120° E). Two Lingshui, Hainan (18.5° 110° E) our previous study. To further QTL on 4, namely qTN4, line CSSL29 with a lower selected ZH9308 develop secondary F2 population. In F2:3 population, qTN4 validated subsequently narrowed down 4.08 Mb region. What more, combined phenotype genotype, dissected into two QTLs, qTN4.1 qTN4.2, F4:5 The qTN4.2 explained 34.31% 32.05% phenotypic variance, additive effect 1.47 1.38, respectively. Finally, fine-mapped 193.55 Kb 175.12 intervals Based genotype phenotype, near-isogenic (NILs) mapping populations. Compared NILCSSL29, (TN), grain setting rate, length (GL), ratio width (LWR) per plant NILZH9308, NIL-qTN4.1ZH9308 NIL-qTN4.2ZH9308 increased, heading date these three earlier than NILCSSL29. Interestingly, among candidate genes except for LOC_Os04g23550, none other has been cloned, indicating existence novel gene-controlling number. These results lay foundation analysis provide theoretical basis application breeding.