摘要
采用遮荫试验,研究了光对9个苜蓿品种苗期形态特征及生长动态的影响。结果表明,不同遮荫处理下苜蓿品种间株高变化有较大的差异,游客表现出最弱的耐阴性;随光照减弱,各品种根颈分枝数、主根粗、二级侧根数、根瘤数、叶片厚度和叶片数均显著下降,表现出较强光环境下更强的形态可塑性;各品种主根长无显著变化,总叶面积动态中新疆大叶、苜蓿王和德宝变化不显著,其他品种显著下降。各品种生物量随遮荫强度增加而显著下降,弱光下各品种生物量对根系的分配明显下降,对茎和叶的分配增加,叶面积比随光强减弱明显增大,相对生长速率随光强减弱显著下降。不同品种同一器官对光环境变化的反应程度不一致,反映了苜蓿各品种耐阴机制的差异。
The seedling morphological characteristics and growth dynamics of nine Medicago sativa varieties under shade were studied.The height of Eureka showed significantly less plasticity than other varieties under different levels of shading.All varieties showed a larger morphological plasticity at lower light intensities than at higher intensities：They developed distinctly fewer crown ramus,root nodes,leaves and secondary lateral roots,thinner leaves and taproots at lower intensities.Light intensity had little effect on the taproot length of all varieties.The leaf area of Xinjiangdaye,Alfaking,and Derby showed no obvious difference when other varieties significantly decreased.With decreasing light intensity,both the gross and root biomass allocation significantly decreased while stem and leaf biomass allocation increased.The leaf area ratio significantly increased but the relative growth ratio was significantly reduced with an increase in shading.The different sensitivity to shading of the same organ of different varieties indicated that there were different mechanisms for shade-tolerance among M.sativa varieties.
出处
《草业学报》
CSCD
北大核心
2010年第3期204-211,共8页
Acta Prataculturae Sinica
基金
南京农业大学青年科技创新基金(Y200713)
国家科技支撑计划项目(2008BADB3B10)资助
关键词
紫花苜蓿
苗期
遮荫
形态
生长响应
Medicago sativa
seedling
shading
morphology
growth response
