混合选择对纳罗克非洲狗尾草种性复壮的影响

Study on the wffects of Setaria sphacelata cv. Narok using bulk selection

采用混合选择法对退化纳罗克非洲狗尾草Setaria sphacelata cv. Narok进行种性复壮研究,结果表明:经2次群体混合选择,复壮品种平均株高为173.2 cm,穗长21 cm,分别比退化品种提高71.53%和57.9%;分蘖数90.4枝/株,抽穗数22.2枝/株,分别比第1次群体混合选择提高188.9%和115.5%;主要穗色褐色达70%。穗长与株高呈极显著正相关(r=0.984,P<0.01);分蘖数与抽穗数呈极显著负相关(r=-0.772,P<0.01)。8月种子产量最高。收种方法对种子质量有影响,割穗收种和田间抖穗收种的种子发芽率分别为9.50%和51.25%,千粒重分别为1.05和2.00 g;收种后牧草鲜草产量达60.2 t/hm2,干物质产量达15.7 t/hm2,均比原种有所提高。

A study on characterization rejuvenation of degenerated species of Setaria sphacelata cv. Narok using bulk selecting was carried out. The average plant height and fringe length in repeated bulk selection were 173.2 and 21.0 cm, increased by 71.5% and 57.9% respectively, compared to the both in control. The numbers of tillering and branch after repeated bulk selection were 90.4 and 22.2, increased by 188.9% and 115.5% respectively, compared to those in the first community selection. Total of 70% fringe had dark brown color. There is a positive correlation between fringe length and number of earring （r = 0. 984, P〈0.01）, numbesr of disport had a negative correlation with the numbers of earring （r =-0. 772, P〈0.01）. The harvesting yield proved that harvesting in August could obtain higher seed yield. Harvesting method significantly affected the quality and quantity of seed production. Seed germination rate was 9.5% and 51.25% by ear cutting and ear shaking with 1 000-grain weight of 1.05 and 2.0 g respectively. The fresh matter and dry matter production were 60.2 and 15.7 t/hm^2, respectively, which were higher than were the degenerated origin cv. Narok .