小麦穗颈维管束遗传特性及其与产量性状的关系

Genetic Characters of Vascular Bundle in the First Internode and Its Relationship with Yield Components of Wheat

为了研究不同水分条件对小麦穗颈维管束发育的影响,为小麦抗旱高产育种提供解剖学依据,以小麦加倍单倍体（DH）群体（旱选10号×鲁麦14）为材料,采用常规石蜡切片法分别检测干旱胁迫和正常灌溉条件下灌浆期小麦穗颈维管束数目及面积,同时分析了维管束遗传特性及其与产量性状的关系。结果表明,干旱胁迫严重抑制小麦穗颈维管束的发育,显著降低小维管束数目和维管束面积,对大维管束数目的影响较小;维管束性状的广义遗传力均较高,分布范围为74.16%-97.51%;DH群体各性状分离范围广泛,均产生了明显超亲的株系;在干旱胁迫条件下,维管束性状与产量性状表现负相关或相关不显著;在正常灌溉条件下,多数维管束性状与总小穗数、结实小穗数、小穗结实率及穗长呈显著或极显著正相关。由此可见,通过增加小麦穗颈大、小维管束数目和面积可保证物质运输“流”的畅通,育种工作中可以结合穗颈解剖结构特征选育高产品种。

In order to understand the effect of different water conditions on the development of vascular bundle in the first internode below ear and the relationship between the vascular bundle traits and yield components in wheat, a doubled haploid （DH） population with 150 lines, derived from a cross between two Chinese common wheat varieties Hanxuan10 and Lumai14 was employed. Paraffin sections were made from the middle part of the first internodes, which were sampled on 14th-15th day after flowering. The vascular bundle traits, its genetic characters and the relationship between the vascular bundle traits in the first internode below ear and yield components under drought stress and well-watered conditions were analyzed, respectively. The results showed that, water stress restrained seriously the development of vascular bundle, such as areas of large, small and total vascular bundle, and the numbers of small and total vascular bundle as well. The broad heritability of vascular bundle was high and ranged from 74. 16% to 97.51%. Phenotypes of the traits separated in broad ranges, a lot of lines showed traits significantly surpassing their parents. Significant and positive correlations between most vascular bundle traits and total spikelet, fertile spikelet, fertile spikelet rate and spike length were identified under well-watered condition, whereas only significant and negative correlation was detected under water stress. Then we concluded that the numbers and areas of large and small vascular bundle traits in the first internode might keep a straightway ＂flow＂ of wheat. Therefore, anatomical characters in the first internode can be considered as the reference criteria for improving the yield in wheat.