不同经度种源地野生狗牙根形态多样性研究

A study on the morphological diversity of wild bermudagrass germplasm resources from regions with different longitudes

以242份来自不同经度种源地的野生狗牙根为试验材料,对其形态指标(颜色、草层高度、叶宽、匍匐茎直径、匍匐茎长、匍匐茎节间长、根冠比、匍匐茎再生长度)和多样性系数(Shannon-Wiener指数、Simpson指数)进行比较。结果表明:(1)不同经度种源地野生狗牙根存在一定的形态差异,大部分形态指标多样性丰富(Shannon-Wiener指数大于2.00),部分形态指标并未呈现经度梯度变化趋势,但小范围内有一定的变化规律;(2)随经度降低,野生狗牙根颜色呈变浅的趋势,低经度种源地(105°E—109°E)材料株型普遍较大,种源地海拔与叶宽、匍匐茎长呈显著正相关,与叶片颜色呈显著负相关,而种源地年均温则与叶宽、匍匐茎长呈显著负相关,与叶片颜色呈显著正相关,年降水量与匍匐茎长呈显著负相关;(3)将经度梯度上的13地野生狗牙根材料按形态学特征大致分为2大类,第Ⅰ类植株低矮,适宜开发坪用功能,第Ⅱ类植株高大,适宜选育用作饲草。

Morphological characteristics(color,grass height,leaf width,stolon diameter,stolon length,stolon internodes long,root-shoot ratio,stolon regrowth length)and diversity indexes(Shannon-Wiener index,Simpson index)of 242 wild Bermudagrass materials from regions with different longitudes were studied.The results showed that:(1)there were some morphological differences in the wild Bermudagrass from different regions,and the diversity of morphological indexes was rich(Shannon-Wiener index was greater than 2.00).Some morphological characteristics did not change along the longitude gradient,but showed a certain change rule in a small range;(2)with the longitude decreasing,the color of wild Bermudagrass tended to be lighter,and the plant types of materials in low longitude regions(105°E-109°E)were generally larger.There was a significant positive correlation between the altitude of the regions and leaf width,stolon length.And a significant negative correlation between the altitude of the regions and leaf color.There was also a significant negative correlation between mean annual temperature of the regions and leaf width,stolon length,and a significant positive correlation between mean annual temperature of the regions and leaf color.The results showed that there was a significant negative correlation between meanannual rainfall and stolon length;(3)according to the morphological characteristics,the wild Bermudagrass materials in13 regions were roughly divided into 2 categories:the cluster Ⅰ was low type and suitable for the turf,the cluster Ⅱ was tall and suitable for the forage.