小麦穗发芽鉴定方法的比较与分析

Comparison and analysis of wheat pre-harvest sprouting screening methods

关键词:  小麦, 穗发芽, 穗发芽鉴定

Key words:  wheat(Triticum aestivum L.), pre-harvest sprouting, sprouting resistance

摘要:

穗发芽是小麦生产中较为严重的灾害之一,易受外界环境的影响,一旦发生不仅会影响产量,而且还会严重影响小麦的品质,因此培育抗穗发芽的小麦品种至关重要。该研究通过对65份小麦材料进行穗发芽试验,比较分析了小麦穗发芽抗性的常用方法,即籽粒发芽法、整穗发芽法和大田穗发芽法。结果表明:三种方法之间均呈极显著正相关关系,而且在1%水平上均存在极显著性差异; 发芽指数与籽粒发芽率的相关性最高,能够更好地评价小麦材料的休眠特性,但不能得出材料的总体抗性; 籽粒发芽法和整穗发芽法的变异程度相对较小,试验条件更易控制,可作为小麦穗发芽抗性评价的简易方法; 多数参试材料的平均籽粒发芽率>平均整穗发芽率>平均大田穗发芽率,且三者差异程度均达到极显著水平,这说明麦穗的外部结构及外部环境对小麦穗发芽的影响显著。因此,籽粒发芽法可以从休眠性方面,对小麦种子资源进行初步筛选; 整穗发芽法可用于穗发芽抗性的进一步鉴定和验证,评价小麦材料穗发芽的综合抗性; 大田穗发芽法较易受自然条件的影响、变异程度较大,其结果可以作为室内发芽试验的参考数据。

Abstract:

Pre-harvest sprouting, easily influenced by the external environment, is one of the serious disasters in wheat production, and once the occurrence not only affects the yield, but also seriously affects the quality of wheat. Therefore, it is very important to develop wheat varieties with resistance to sprouting. For a more comprehensive evaluation of wheat sprouting resistance, the seed germination, whole spike germination and field intact spike germination, the basic methods to evaluate the germination of wheat, were compared and analyzed in the research by germinating test with 65 varieties and breeder's lines. The results of correlation and difference analysis showed that the germination rates obtained in the three methods were significantly positive correlated, and significantly different at the 1% level. The correlation between germination index and seed germination rate was the highest, which could better evaluate the dormancy characteristics of wheat, but could not get the overall resistance. The coefficients of variation of the seed germination and the whole spike germination were smaller, and the test conditions were easier to control, compared with the field intact spike, so they were the simple methods to evaluate the resistance of wheat spike sprouting; The average seed germination rates of most materials were the highest and the field intact spike germination rate was the smallest for the most of accessions, and the differences among the three methods reached extremely significant levels, which showed that the external environment and the external structure of wheat on spike germination was significantly affected, so it was very important to strictly control the external environment during test. Therefore, the seed germination method could be used to screen germplasm first from the dormancy, to seek resistance materials from the source, and the whole spike germination method could be used to further verify of the sprouting resistance, to evaluate the comprehensive resistance of the pre-harvest sprouting. Meanwhile, the field intact spike germination was more susceptible to natural conditions, and its variation degree was larger. Therefore, the results could be used as reference data for laboratory germination tests and it is necessary to combine the three methods in order to obtain a more accurate result.