麦田看麦娘属杂草种群消长的生物学基础研究

以麦田杂草看麦娘和日本看麦娘为材料，比较了两种杂草在生长速率、生育期、繁殖能力和资源利用能力等生物学特性差异。结果表明，日本看麦娘的分蘖数、主茎叶龄和株高分别是看麦娘的１．１７、１．１５和１．２６倍。与看麦娘相比，日本看麦娘出苗期早６天，成熟期晚６天，全生长期长１２天；看麦娘的单穗籽实数和繁殖系数高于日本看麦娘，但受低成穗率和籽这萌发率限制，其繁殖能力仍低于日本看麦娘８．８％。置换系列试验表明，日

STUDIES ON THE BIOLOGICAL BASES FOR DYNAMICS OF ALOPECURUS POPULATIONS IN WHEAT FIELDS

Alopecurus aequalis Sobol. and A. japonicus Steud. were two noxious weeds which grow in wheat fields in the agricultural regions with rice-wheat cropping system. Experiments were conducted to compare the differences of biological characteristics such as growth rate and duration, reproductive capacity and resource utilization between A. aequalis and A. japonicus. The results showed that the tiller number, leaf number in primary shoot and plant height of A. japonicus were 1. 17,1. 15 and 1. 26 times those of A. aequalis, respectively. A. japonicus emerged 6 days earlier and riped 6 days later than A. aequalis did. So the growth duration of A. japonicus was 12 days longer than that of A. aequalis. Compared with A. japonicus, A. aequalis possessed larger grain number per ear and reproductive coefficient, but its reproductive capacity was still lower due to limitation of low rate of germination and lower percentage of ear-bearing tiller. Moreover, results of replacement series experiment showed that A. japonicus presented stronger ability to utilize resources. Therefore, the authors propose that A. japonicus is superior to A. aequalis in competitiveness and that interspecific competition is a primary factor affecting the dynamics of Alopecurus populations.