华南地区野生狗牙根植物学形态特征变异研究

A study on morphological variations of Cynodon dactylonin south China

对96份华南地区野生狗牙根种源的11个植物学特征进行研究。结果表明,1)狗牙根的植物形态学特征存在广泛变异,其变异系数排序为:叶毛(129.78%)>草层高度(38.18%)>叶长(37.61%)>密度(32.41%)>节间长(21.80%)>花序长(18.44%)>小穗数(15.08%)>节间直径(14.49%)>叶宽(14.05%)>穗枝数(9.45%)>叶色(7.64%)。2)狗牙根植物形态学特征间存在明显相关性,营养器官表现为叶片宽大,茎杆粗壮高大,叶色浅且多毛的狗牙根,花序长、穗枝数及小穗数多;反之,草层低矮的狗牙根,质地(叶宽)好,密度大,叶色深。3)随着纬度的增加,华南地区狗牙根种源的叶色变深,节间变粗,而穗枝数及小穗数明显变少,随着经度的增加,节间明显变粗,草层变高,花序变长,而小穗数变少。4)聚类分析可将华南地区狗牙根分为3个形态类型。

Eleven morphological characteristics of 36accessions of wild Cynodon dactylon from south China were observed and analyzed.The results showed that：1）Abundant morphological variation existed in accessions of C.dactylon.Their coefficients of variation were ranked as follows：leaf hairs（129.78%）〉turf height （38.18%）〉leaf length（37.61%）〉turf density（32.41%）〉internode length（21.80%）〉inflorescence length （18.44%）spikelet number（15.08%）internode diameter（14.49%）〉leaf width（14.05%）〉inflorescence branch number（9.45%）〉leaf color（7.64%）.2）Morphological characteristics of C.dactylonhad significant relationships.Those with high turf had lighter color,more leaf hairs,longer and wider leaves,stronger stems, longer inflorescence,and more inflorescence branches and spikelets,whereas those with low turf had the opposite characteristics.3）With higher latitudes,C.dactylon had darker leaf color,stronger stems,fewer inflorescence branches and spikelets.It also became stronger,with higher turf,longer inflorescences but fewer spikelets as the longitude increased.4）Based on eleven morphological characteristics,accessions of wild C. dactylonfrom south China were clustered into three morphological types.