【作者】 马克群；

【导师】 刘建秀；

【作者基本信息】 南京农业大学 ， 园林植物与观赏园艺， 2006， 硕士

【摘要】 本文针对目前生产上主栽杂交狗牙根品种在坪用质量和适应性方面存在的问题，利用国内外狗牙根和非洲狗牙根的优良选系进行种间杂交，从形态学和细胞学两方面对杂交后代进行鉴定，并对杂种后代的坪用价值、抗寒性及生长速度进行评价，希望选育出坪用质量更好，抗性更强的国产杂交狗牙根新品种，以满足我国草坪业快速发展的需要。研究结果如下： 1 狗牙根和非洲狗牙根杂交后代的鉴定 在形态学鉴定方面，通过对10个狗牙根和2个非洲狗牙根的13个外部性状实地观测和统计分析，结果表明，叶片宽度、节间直径、穗支数、穗支长度、小穗长度、叶片色泽、匍匐茎色泽和花柱色泽等8个外部性状可作为鉴别这两个种的形态指标；通过对12个亲本和36个后代的8个形态学指标进行分析，初步鉴定14个后代为自交种或母本间的杂交种的可能性很大；4个后代系自交种或母本间的杂交种可能性较大；C08有可能为种间杂交种；17个后代为种间杂交种的可能性很大。 在细胞学鉴定方面，观测分析了12个杂交亲本的染色体数目，结果为：母本非洲狗牙根主要是2n=18，存在少部分染色体数目的变异；父本狗牙根染色体数目变异范围很大，都存在多个染色体倍性水平和非整倍体；狗牙根染色体数目绝大多数都在18-36之间，并以整倍体为主。通过对36个杂交后代的染色体的倍性进行分析，结合形态学鉴定结果，确定19个后代为自交种或母本间杂交种，17个后代为种间杂交种。 2 狗牙根和非洲狗牙根杂种后代的评价 在坪用价值的评价方面，选择密度、质地、色泽、均一性、抗病性(锈病)和青绿期等6个指标，对17个杂种后代进行评价，结果表明：杂种后代的坪用价值变化范围为3.17-5.18；C35的坪用价值价值最高，好于两对照‘Tifgree和‘Tifway’，后代C36、C07的得分略高于对照’Tifway’而低于’Tifgreen’，C06、C14、C05和C19等4个后代稍低于对照‘Tifway’，坪用价值也较好。 在抗寒性鉴定方面，用电导率的方法，以‘Tifway’和‘Tifgreen’为对照，对7个优良杂交狗牙根的抗寒性进行评价，结果表明：参试的7个狗牙根杂种后代半更多还原

【Abstract】 In order to improve turf quality and adaption of main Cynodon cultivators, some excellent accessions of C. dactylon and C. transvaalensis were hybridized to creat new Cynodon cultivators with better turf quality and stronger adaption so as to meet the need of the rapid developement of turf grass in our country. The crossing progenies were identified by morphological characteristics and chromosome ploid level, then turf quality, cold resistance and growth rate of some hybrids between female and male parents were evaluated in this dissertation. The main results are as follows: 1 Identification of Hybrids between C. dactylon and C.transvaalensisThirteen morphological characteristics of ten selections of Cynodon dactylon and two selections of Cynodon transvaalensis were analyzed and compared in this experiment. The results showed that their 8 morphological characteristics, including leaf width, internode diameter, inflorescence number, inflorescence length,leaf color, stolon color and style color,can be used to distinguish two species. Eight morphological index of 12 parents and 36 hybrids were analyzed in this experiment. The result shows as follows: Fourteen hybrids are likely, with 4 ones may be, self-copulation or hybrids between female parents . C08 can be and another 17 hybrids are likely to be hybrids between 2 speciesChromosome number of parents of 10 Cynodon dactylon and three Cynodon transvaalensis were studied in this experiment. The preliminary result showed that the main chromosome number of C.transvaalensis is 2n=18 except few chromosome number variation. Very high chromosome number variation exists in C.dactylon including a lot of ploid levels and aneuploidy: Most chromosome number are between 18 and 36 and more than two-third cells in nine C.dactylon are euploid. Chromosome ploid level of 36 Cynodon hybrids were analyzed. Synthesizing the results of morphological and cellular identification, 19 hybrids are almost identificated to be self-copulation or hybrids between female parents and another 17 ones have very high chance to be hybrids between female and male parents.更多还原