贵州地区不同秋眠级苜蓿品种根系发育能力研究

A study on root system development ability of alfalfa cultivars with different fall dormancy rates in the Guizhou area

从根系发育角度对美国11个秋眠级标准对照苜蓿品种在贵州地区的适应性进行研究。结果表明,苜蓿随着秋眠级升高,根颈直径呈先减小后增大的趋势,最大的是UC-1887(FD10),为1.439cm;主根长度呈先增长后减小的趋势,最长的是Pierce(FD8),为59.75cm;侧根数逐步减少,最多的是Vernal(FD2),为19.33;最少的为Pierce(FD8),为12.25。主根直径、主根体积、主根生物量、侧根体积、侧根生物量及根系体积、根系生物量都呈增大的趋势,苜蓿第1年根系主要集中在0～20cm土层,根系体积所占比例为77.82%～92.35%,根系生物量所占比例为75.14%～90.96%。通过聚类分析及不同秋眠级苜蓿品种的综合表现,在贵州地区,苜蓿根系发育能力较强的秋眠级为7～10。

The abilities of different fall-dormancy alfalfa cultivars to develop root systems were studied in the Guizhou area to analyze their adaptabilities. Root neck diameter initially decreased but then increased as the fall dormancy rate increased. Root neck diameter of UC-1887 （FD10） was the largest （1. 439 cm）. Taproot length initially increased, then decreased with Pierce （FD8） having the longest taproots （59.75 cm）. The number of secondary roots gradually, decreased： Vernal （FD2） had the most （19. 33）, and Pierce （FD8） the fewest （12.25）. Taproot diameter, taproot volume, taproot biomass, lateral root volume, lateral root biomass, root system volume, and root system biomass tended to increase as the fall dormancy rate increased. First year underground root systems grew mainly in the 0--20 cm depth zone. The proportions of root system volume were 77.82%--92.35% and root system biomass rates were 75.14%0--90. 960/oo. Based on the integrated performance and cluster analysis of alfalfa with different fall dormancy rates, the fall dormancy rates of alfalfa with the greatest root system development ability ranged from 7 to 10.