多效唑和乙烯利对谷子穗颈、穗部性状及灌浆的影响

为探究既能抑制谷子植株的贪青徒长,又不影响谷子产量的最佳多效唑和乙烯利处理,以农大8号为试验材料,采用随机区组设计,在谷子不同生育时期分别叶面喷施多效唑和乙烯利,研究2种植物生长调节剂单施[多效唑分别于拔节期前(A1)、拔节期(A2)、孕期期(A3)喷施;乙烯利分别于孕穗期(B1)、抽穗期(B2)、灌浆期(B3)喷施]和互作(A1B1、A1B2、A1B3、A2B1VA2B2、A2B3VA3B1、A3B2、A3B3)对谷子穗颈、穗部性状及灌浆的影响。结果表明,多效唑、乙烯利单施处理下,谷子穗颈粗、穗颈干物质显著提高,但其他穗颈参数无显著差异;谷子穗粗显著增加,在A1处理下达到最大值,较CK增加5.39%,穗重、穗粒重均在B2处理下最高,较CK分别增加7.25%、6.94%,穗长、穗码数无显著差异;籽粒灌浆速率有所提高,但秕谷率无显著变化。多效唑、乙烯利互作处理下,谷子穗颈粗、穗颈抗折力及干物质重显著增加,穗颈弯曲力矩、穗颈重心高度及含水量明显下降;谷子的穗长、穗码数显著减少,穗粗显著增加,在A1B3处理下达到最大,与CK相比,其穗长、穗码数分别减少20.11%、9.75%,穗粗增加10.15%,穗重、穗粒重均在A2B2处理下达到最大值,较CK分别增加11.45%、9.50%;随着籽粒灌浆速率的提高,秕谷率显著降低,在A2B2处理下达到最小值,较CK降低50.00%。表明与单施相比,两种调节剂互作效应更显著。在谷子拔节期前或拔节期喷施300 mg·L^(-1)多效唑后,在抽穗期或灌浆期追施400 mg·L^(-1)乙烯利最为适宜,而在孕穗期追施乙烯利会降低穗粒重,导致产量下降。本研究结果为谷子的化学调控和高产栽培提供了理论依据。

粳型超级稻品种‘沈农265’穗部和穗颈维管束性状的QTL剖析

采用粳型超级稻品种‘沈农265’和普通品种‘丽江新团黑谷’的176株F2群体分析24个穗部和穗颈维管束数量性状位点(QTL)的结果显示,共检测到37个QTL,它们分布在水稻的第1、2、3、4、5、6、7、8、9和12号染色体上,单个QTL对性状表型贡献率在11.0%～65.0%之间,其中大于20%的有15个。这些QTL分别在第3、4、6、9和12号染色体上,以6个QTL簇(QCR)的形式存在。QCR-3和QCR-12控制穗部和穗颈维管束性状,QCR-4a、QCR-4b、QCR-6和QCR-9控制穗部性状,在这些区域已经定位了多个控制穗部性状的QTL,说明紧密连锁或成簇分布是穗颈维管束性状和穗部性状高度相关的遗传学基础之一。

籼粳亚种间杂交后代穗颈维管束数与穗部性状关系的研究

籼粳亚种间杂交后代穗颈大维管束数与穗颈小维管束数、１次枝梗数、１次枝梗粒数、２次枝梗数、２次枝梗粒数和穗粒数均呈显著或极显著的正相关；穗颈小维管束数与１次枝梗数、２次枝梗数、２次枝梗粒数和穗粒数亦呈显著或极显著的正相关；穗粒数主要由２次枝梗粒数决定，而２次枝梗粒数主要由２次枝梗数决定，穗颈大、小维管束数和１次枝梗数通过２次枝梗数影响穗粒数；穗颈维管束性状主要受遗传因素控制。

QTL Analysis of Rice Peduncle Vascular Bundle System and Panicle Traits

A double haploid (DH) population of rice (Oryza sativa L.) derived from anther culture of ZYQ8/JX17, a typical indica and japonica hybrid, was used for genetic analysis of rice peduncle vascular system and panicle traits. The number of large vascular bundles (LVB), the number of small vascular bundles (SVB) in the peduncle, and the panicle traits including the number of primary rachis branches (PRB), the number of spikelets per panicle (SNP), peduncle top diameter (PTD), and panicle length (PL) were investigated in the parents and DH lines. The quantitative trait loci (QTLs) for each trait were analyzed based on the constructed molecular linkage map of this population. Three QTLs for LVB (qLVB_1, qLVB_6 and qLVB_7) were detected on chromosomes 1, 6, and 7, respectively. Two putative QTLs for SVB (qSVB_4 and qSVB_6) were mapped on chromosomes 4 and 6 respectively. Four QTLs (qPRB_4a, qPRB_4b, qPRB_6 and qPRB_7) on chromosomes 4, 6, and 7, respectively, were detected for PRB. Three QTLs (qSPN_4a, qSPN_4b and qSPN_6) were identified on chromosomes 4 and 6, respectively, which could significantly affect SPN. Five QTLs for PTD (qPTD_2, qPTD_5, qPTD_6, qPTD_8 and qPTD_12) were identified on chromosomes 2, 5, 6, 8, and 12, respectively. Three QTLs for PL (qPL_4, qPL_6 and qPL_8) were detected on chromosomes 4, 6, and 8, respectively. Clustering of QTLs, such as qLVB_6, qSVB_6, qSNP_6, qPTD_6, and qPL_6 detected in the interval G122_G1314b on chromosome 6, was found. These results suggest that some QTLs for peduncle vascular bundle system are possibly responsible for the panicle traits.