张瑜 严琳玲 虞道耿 王文强 刘国道

摘  要：为探究不同柱花草的抗旱性强弱，构建柱花草资源抗旱评价体系，以85份引进柱花草为试验材料，分别测定0（CK）、10%和20%质量浓度的PEG-6000渗透液胁迫下萌发期的相对发芽势、相对发芽率、相对胚根长、相对胚轴长、萌发抗旱指数共5项指标，分析不同干旱胁迫对柱花草种子萌发的影响，并结合隶属函数法综合评价柱花草抗旱性能。结果表明：低浓度的PEG对柱花草种子的萌发有一定促进作用，高浓度PEG降低了柱花草种子的相对发芽势和相对发芽率，阻碍了胚芽和胚根的生长，种间表现出较大差异。其中抗旱型材料为头状柱花草CIAT 2250、大头柱花草CIAT 2113和CIAT 1942、蔓性柱花草CIAT 10182，不耐旱材料有墨西哥柱花草CIAT 1590、卡尔奇柱花草CIAT 1616和CIAT 1624。本研究结果为引进柱花草资源抗旱性评价、抗旱品种选育及其机理研究提供了理论依据。

关键词：柱花草;引进;PEG胁迫;萌发特性

中图分类号：S541.9      文献标识码：A

Abstract： In order to investigate the drought resistance of different Stylosanthes， an evaluation system for the drought resistance of Stylosanthes resources was constructed. Using 85 imported Stylosanthes as the test material， the seed relative germination rate， relative germination energy， relative radiele length， relative plumule length， germination drought resistance index were measured under distilled water （CK）， 0.2 and 0.6 MPa PEG-6000 stress. The drought resistance ability of the germplasms was evaluated comprehensively by the subordinate function method by analyzing the effects of different drought stress on the seed germination of Stylosanthes. Low concentration of PEG had a certain promotion on the germination of seeds. High concentration of PEG reduced the relative germination potential and relative germination rate of Stylosanthes seeds， hindered the growth of embryo and radicle， and showed great differences among species. Among them， drought resistant materials were S. capitata CIAT 2250， S. macrocephala M.B. CIAT 2113 and S. macrocephala M.B. CIAT 1942， S. montevidensis Vogel CIAT 10182， and non-drought resistance materials were S. mexicana Taub. CIAT 1590， S. calcicola Small CIAT 1616 and S. calcicola Small CIAT 1624. The result of the study would provide a theoretical basis for the drought resistance evaluation of introduced resources， breeding of drought resistant varieties and drought resistance mechanism research of Stylosanthes.

Keywords： Stylosanthes; introduction; PEG stress; germination characteristics

DOI： 10.3969/j.issn.1000-2561.2020.04.007

柱花草属植物（Stylosanthes SW.）是热带、亚热带地区重要的豆科牧草和饲料植物资源，主要用于饲喂牲畜、草地良种化改造和林、果草生态工程建设，在水土流失治理和退耕还草中也发挥重要作用[1-5]。但柱花草抗旱性、耐寒性和抗炭疽病性较低等问题，严重威胁柱花草的生产和推广种植[6-8]。因此，开展柱花草种质资源抗旱鉴定与抗旱品种筛选，一方面可以促进高产抗旱品种的推广应用，另一方面可以为柱花草抗旱育种提供亲本材料。

萌发期是饲草生长的关键时期，直接决定饲草的出苗期与出苗率、实际密度与产量等[9]。……