小麦中国春背景下长穗偃麦草染色体代换对苗期根系形态性状的效应

以小麦中国春-长穗偃麦草二体代换系为材料, 利用基于图像扫描的根系分析系统对幼苗根系的总根长、根系表面积和根系平均直径等性状进行了研究, 计算了该代换系及其亲本中国春幼苗根系的分形维数。结果表明, 长穗偃麦草的3E^e、5E^e和7E^e染色体与单株根数性状有关, 代换入中国春后其单株根数降低; 1E^e、2E^e和4E^e染色体与总根长性状和根系总表面积性状有关, 导致根长和根系总表面积增加; 而决定根系平均直径的基因分散于长穗偃麦草各条染色体上。根系的分形维数与单株根数、根系总长度、表面积、根系平均直径显著相关, 因此分形维数能够作为一个综合指标反映中国春及其代换系的综合特征, 但其应用尚需进一步研究。

Effects of Exogenous Chromosomes on Root Characteristics in Triticum aestivum-Lophopyrum elongatum with Chinese Spring Background

The effects of exogenous chromosomes on root morphology were studied with the disomic substitution series of Triticum aestivum L. cv. Chinese Spring-Lophopyrum elongatum (Host) A. Löve. Scanner-based image analysis was used to investigate total root length, surface area, mean diameter, and number of root per plant. The fractal dimensions of young root systems were also calculated. Compared with Chinese Spring, there were fewer roots per plant in 3E^e, 5E^e, and 7E^e substitutions and larger total root length and surface area in 1E^e, 2E^e, and 4E^e substitutions, indicating that genes associate with the above characteristics on the corresponding chromosomes respectively. But the genes controlling average diameter were found on every chromosome of L. elongatum. The fractal dimension of seedling root systems was significantly correlated with the above 4 root parameters included in root growth models (0.757**≤r≤0.845**). It is suggested that the fractal dimension can be used as an integrated index for summarizing root morphological characteristics of Chinese Spring and its substitutions after further studies.