不同种群巨柏种子表型及萌发特性

Seed Phenotype and Germination Characteristics of Different Populations of Cupressus gigantea

以西藏林芝、米林及朗县3个种群的巨柏(Cupressus gigantea)种子作为研究材料,测定种子的长度、宽度、高度、种形指数、千粒重和种子发芽势、发芽率等指标,探索不同居群巨柏种子表型特征差异和种子萌发特性。结果表明,3个种群巨柏种子表型特征5个指标均存在差异,种子平均长度为:林芝=朗县(4.14 mm)>米林(3.99 mm);种子宽度为:米林(3.28 mm)>朗县(3.11 mm)>林芝(3.14 mm);种子高度为:米林(1.94 mm)>林芝(1.92 mm)>朗县(1.82 mm);千粒重为:米林(3.81 g)>林芝(3.68 g)>朗县(3.47 g)。从种子性状指标间的变异系数来看,朗县种形指数和千粒重变化幅度最小,种子质量最稳定。3个种群巨柏种子的发芽率均很低,但差异显著。朗县种群种子萌动较快,出芽整齐,发芽率最高(42%),与种子表型特征一致。因此,进行巨柏种苗繁育时,选择朗县种群的种源最佳。

In this paper,the seeds of Cupressus gigantea from three populations in Nyingchi County,Milin county and Langxian County of Tibet were selected as research materials.The seed length,width,height,seed shape index,1000 seed weight,seed germination potential and germination rate were measured,and the phenotypic characteristics and seed germination characteristics of different populations were explored.The results showed that there were differences in five indexes of seed phenotypic characteristics among the three populations.The average seed length was Nyingchi=Lang county(4.14 mm)>Milin(3.99 mm);Seed width:Milin(3.28 mm)>Lang county(3.11 mm)>Nyingchi(3.14 mm);Seed height:Milin(1.94 mm)>Nyingchi(1.92 mm)>Langxian(1.82 mm);1000 grain weight:Milin(3.81 g)>Nyingchi(3.68 g)>Langxian(3.47 g).From the variation coefficient of seed character indexes,the variation range of seed shape index and 1000 grain weight in Langxian county was the smallest,and the seed quality was the most stable.The seed germination rate of the three populations was very low,but the difference was significant.The seeds of Langxian population germinated rapidly,sprouted neatly,and the germination rate was the highest(42%),which was consistent with the performance effect of seed surface characteristics.It can be seen that Langxian population was the best germplasm for the breeding of Cupressus gigantea seedlings.