Zheng B S, Yang L, Zhang W P, Mao C Z, Wu Y R, Yi K K, Liu F Y, Wu P
The State Key laboratory of Plant Physiology and Biochemistry, College of Life Science, Zhejiang University, 310029 Hangzhou, P. R. China.
Theor Appl Genet. 2003 Nov;107(8):1505-15. doi: 10.1007/s00122-003-1390-1. Epub 2003 Aug 15.
To investigate the genetic factors underlying constitutive and adaptive morphological traits of roots under different water-supply conditions, a recombinant inbred line (RIL) population derived from a cross between the lowland rice variety IR1552 and the upland rice variety Azucena with 249 molecular markers, was used in cylindrical-pot experiments. Eighteen QTLs were detected for seminal root length (SRL), adventitious root number (ARN), and lateral root length (LRL) and lateral root number (LRN) on the seminal root at a soil depth of from 3 to 6 cm under flooding and upland conditions. One identical QTL was detected under both flooding and upland conditions. The relative parameters under the two water-supply conditions were also used for QTL analysis. Five QTLs for upland induced variations in the traits were detected with the positive alleles from Azucena. A comparative analysis was performed for the QTLs detected in this study and those reported from two other populations with Azucena as a parent. Several identical QTLs for root elongation were found across the three populations with positive alleles from Azucena. Candidate genes were screened from ESTs and cDNA-AFLP clones for comparative mapping with the detected QTLs. Two genes for cell expansion, OsEXP2 and endo-1,4-beta-D-glucanase EGase, and four cDNA-AFLP clones from root tissues of Azucena, were mapped on the intervals carrying the QTLs for SRL and LRL under upland conditions, respectively.
为研究不同供水条件下根系组成型和适应性形态特征的遗传因素，利用由低地水稻品种IR1552和高地水稻品种Azucena杂交产生的、具有249个分子标记的重组自交系（RIL）群体，进行了圆柱钵试验。在淹水和旱作条件下，在土壤深度3至6厘米处，检测到了与种子根长度（SRL）、不定根数（ARN）、侧根长度（LRL）以及种子根上的侧根数（LRN）相关的18个QTL。在淹水和旱作条件下均检测到一个相同的QTL。还利用两种供水条件下的相对参数进行了QTL分析。检测到5个与旱作条件下性状诱导变异相关的QTL，其增效等位基因来自Azucena。对本研究中检测到的QTL与另外两个以Azucena为亲本的群体报道的QTL进行了比较分析。在这三个群体中发现了几个相同的与根伸长相关的QTL，其增效等位基因来自Azucena。从EST和cDNA - AFLP克隆中筛选候选基因，以便与检测到的QTL进行比较定位。分别将两个参与细胞扩张的基因OsEXP2和内切 - 1,4 - β - D - 葡聚糖酶EGase以及来自Azucena根组织的4个cDNA - AFLP克隆定位到旱作条件下携带SRL和LRL相关QTL的区间上。
