不同海拔高度短穗兔耳草克隆生长及克隆繁殖特征

研究了青藏铁路和青藏公路沿线 5个不同海拔高度样地中短穗兔耳草克隆生长和克隆繁殖的特征.结果表明,不同海拔高度短穗兔耳草匍匐茎数量、匍匐茎长度、基株干重、匍匐茎干重和无性系分株干重等均存在极显著差异(P<0. 01);匍匐茎数量与海拔高度之间存在明显的负线性相关性(P=0. 046 4);匍匐茎长度、基株干重、匍匐茎干重、单位长度上匍匐茎干重、无性系分株干重和匍匐茎分株总干重 /基株干重比值均与海拔高度之间存在极显著的二次多项式相关性(P<0. 01),但匍匐茎长度、匍匐茎分株总干重 /基株干重随海拔高度的变化趋势与基株干重、匍匐茎干重、单位长度上匍匐茎干重、无性系分株干重随海拔高度的变化趋势相反.在短穗兔耳草分布的海拔范围内,其克隆繁殖和克隆生长有一个“最佳”海拔高度,远离这一高度,其克隆繁殖和克隆生长会受到一定限制. 图 6表 2参 18

CHARACTERISTICS OF CLONAL GROWTH AND REPRODUCTION OF LAGOTIS BRACHYSTACHYA AT DIFFERENT ALTITUDES

The characteristics of clonal growth and reproduction of Lagotis brachystachya collected from 5 habitats at different altitudes in the Qinghai-Tibetan Plateau were studied. The results showed that there were significant differences in numbers of stolons, length of stolons, dry weight of genets, dry weight of stolons and dry weight of ramets of L. brachystachya in different plots with different altitudes (P<0.01). The numbers of stolons of L. brachystachya in the plots were negatively correlated with altitudes P=0.046 4. The length of stolons, dry weight of genets, dry weight of stolons, dry weight of ramets, dry weight of stolon and ramet/dry weight of genet of L. brachystachya at different altitudes could be predicted by quadratic models (P< 0.01). In its distribution area, there is an "optimal" altitude for clonal growth and reproduction of L. brachystachya(P< 0.01). Fig 6, Tab 2, Ref 18