大豆野生与栽培资源苗期耐淹性的鉴定、生态区特征和优异种质发掘

EVALUATION,ECO-REGION CHARACTERIZATION AND ELITE GERMPALSM IDENTIFICATION OF SUBMERGENCE TOLERANCE AT SEEDLING STAGE IN WILD AND CULTIVATED SOYBEANS

大豆资源耐涝性鉴定,是开展大豆耐涝育种的基础。耐涝性可分为耐湿(渍)性和耐淹性。研究旨在通过对大豆资源的耐淹性评价筛选出耐性强的种质,为大豆耐涝性育种提供耐源。抽取不同来源地的栽培大豆和野生材料,以相对死苗率为鉴定指标,在苗期进行耐淹性盆栽鉴定试验。结果表明,野生和栽培大豆耐淹性均存在相当大的遗传变异;野生大豆中的极端耐淹材料略比栽培大豆的多,但在全国二者大部分材料的耐淹性差异不大;野生大豆的耐淹性在区域内和区域间均存在一定的变异,栽培种的耐淹性在区域内的变异比区域间的变异大,各个区域内均存在丰富的变异,变异系数均在30.0%以上。耐淹性与地理纬度、种皮色、籽粒大小、生育期长短及脂肪含量等有低程度相关;筛选出N24835.0、N24850.0、N23444.0、N04974.1等11份耐淹性极强的野生和栽培优异种质。

Identification of germplasm with flooding tolerance is a basic work in breeding for tolerance in soybean. There are two facets in flooding tolerance,i, e. tolerance to soil waterlogging and tolerance to submergence. The objective of the present research was to establish an evaluation system for submergence tolerance of soybeans at seedling stage and then use it to evaluate the germplasm accessions from different eco-regions and screen for elite accessions highly tolerant to submergence at seedling stage for breeding programs. The cultivated soybean （Glycine rnax（L. ） Merr. ）and annual wild soybean （Glycine soja Sieb ＆ Zucc. ）accessions from different eco-regions were sampled and used in this experiment. The submergence experiment of soybean was carried out at seedling stage with artificial flooding in pot experiment under randomized complete blocks design. The relative death percentage was used as tolerance index. There were significantly genetic differences both among the genotypes of wild and cultivated soybean. The frequency of highly tolerant wild soybean was slightly more than that of cultivated soybean, but most part of both cultivated and wild soybean was intermediate and less sensitive to submergence. There existed certain amount of variation of submergence tolerance both within and among eco-regions in G. soja, while in G. max the among eco-region variation was smaller than the within eco-region variation, of which the CV values were all more than 30.0%. There showed a weak correlation between submergence tolerance and some traits, including geographical latitude, seed coat color, 100-seed weight,maturity date, and fat content. Eleven elite accessions with high tolerance to submergence,including eight G. soja accessions and three G. max accessions, such as N24835. 0, N24850.0,N23444.0,N04974.1 were identified and selected,which will be important sources for future submergence tolerance breeding programs.