干热河谷优良乡土草种三芒草驯化应用研究

Taming Breeding of a Superior Grass Aristida adscensionis Native to Dry and Hot Valley Area

为选育野生三芒草的栽培驯化品种,采用群体选育的方法,以株高、穗长为其表型选择性状进行野生三芒草优异群体的筛选,并开展相应的田间试验。结果显示:栽培驯化可在保证其优良性状的前提下有效促进三芒草的生长,提高其结实性能及种子发芽率,基于栽培驯化后不同性状间的相关性分析,可考虑将株高作为单一选择性状进行优势个体的选择标准;栽培驯化后二次选择出的优选群体,表现出了较好的遗传稳定性,具有生长快、适应性强、生物量大及生态修复效果好的特点。生产应用栽培条件下,其子代种植3个月时的株高、叶长、分蘖数、生殖枝数、穗长、小穗数及小穗种子数可达102.1 cm、27.1 cm、10.8枝、7.5枝、25.1 cm、10.9枝和16.5粒,地上及地下部分的鲜生物量则达16.44 t/hm^(2)和4.53 t/hm^(2);从种植(播种)到覆盖度达到75%所需要的时间仅为40 d,较野生群体可提前20 d达到满足水土保持所需的盖度,生态修复效果良好,可作为野生驯化品种在我省干热和半干旱的亚热带季风地区推广应用。

With the purpose of breeding cultivars of Aristida adscensionis L.,seeds of wild A.adscensionis L.were collected in Yuanmou county of Yunnan province and used as the breeding materials.The strategy of group selection was adopted,and the plant height and fringe length were used as the selection traits.Moreover,field experiments were conducted.The results showed that cultivation and acclimation of the wild A.adscensionis L.could significantly promote its growth,enhance the fruiting ability and seed germination ratio,and its superior characters could be maintained.According to the correlation analysis on different characters,plant height could be chosen as the standard for superior group selection.Through domestication and cultivation,the selected superior groups showed the performance of fast growth,high adaptability,big biomass and promising ecological restoration function;and the hereditary was stable.Under the condition of productive cultivation,the three months old progenies of A.adscensionis L.showed promising growth performance,the plant height,leaf length,tiller number,number of fertile tillers,fringe length,number of fringe,and number of seeds in fringe were 102.1 cm,27.1 cm,10.8,7.5,25.1 cm,10.9 and 16.5,respectively.The fresh weight of aboveground part and underground part were 16.44 t/hm^(2) and 4.53 t/hm^(2).Besides,it took only 40 days from seeding to the coverage of 75%,which was 20 days faster than planting with the wild seeds,the selected A.adscensionis L.could be extended in arid and semi-arid areas in subtropical monsoon region of Yunnan province.