Studies On The Characteristics Of Flowering And Seed Setting In Hordeum Brevisubulatum And Hordeum Bogdanii

In order to breed and promote utilization of high-quality varieties of Hordeum brevisubulatum and Hordeum bogdanii in the future,this study focused on the flowering and seed-setting characteristics of H.brevisubulatum and H.bogdanii in Beijing academy of agricultural and forestry sciences and Zhangjiakou comprehensive test station of national industrial pasture technology system in Chabei management zone of Zhangjiakou from April to October in 2019.The flowering and seed-setting patterns of H.brevisubulatum and H.bogdanii in the two regions were investigated.The research is divided as the follows:(1)Studies on the flowering characteristics of H.brevisubulatum and H.bogdanii in Beijing and Zhangjiakou areas.The results showed that the flowering in both H.brevisubulatum and H.bogdanii began from the middle-upper part of the spike,and then opened to the two ends,respectively.The pollen activity of H.brevisubulatum in Beijing was 57%and that of H.brevisubulatum in Zhangjiakou was 65%.The pollen activity of H.bogdanii in Beijing was 62% and that of H.bogdanii in Zhangjiakou was 71%.The pollen activity of H.brevisubulatum and H.bogdanii in Beijing area was lower than that in Zhangjiakou area.Within one day,the pollen activity showed regular changes.In a certain temperature,the pollen activity increased with the increase of the temperature,and decreased when the temperature was higher than 30℃.The optimum temperature for pollen activity was 23 ～ 30 °C.The pollen activity of florets in different positions on a single panicle was different.Through the study on the stigma receptivity of H.brevisubulatum and H.bogdanii,it was found that the stigma receptivity of H.brevisubulatum and H.bogdanii in Beijing area was lower than that in Zhangjiakou area.In a certain temperature,the stigma receptivity was promoted with the increase of temperature.When the temperature is higher than 30℃,the stigma receptivity decreased.The stigma receptivities at different positions on a single panicle were different,and stigma receptivities at the apex were lower than those at the middle and base.(2)A comparative study on the seed setting rate of natural cross-pollination and self-pollination between H.bogdanii and H.brevisubulatum showed that the natural cross-pollinated setting rate of H.brevisubulatum in Beijing was 40%,and that of H.bogdanii was 44%.In Zhangjiakou area,the seed setting rate of H.brevisubulatum was 49%and that of H.bogdanii was 52%.The packaged self-pollination assays of H.bogdanii and H.brevisubulatum showed that the self-pollinated seed-setting rate of both H.bogdanii and H.brevisubulatum were 0%,and they were cross-pollinated plants.(3)Studies on the seed shattering rate of H.brevisubulatum and H.bogdanii in Beijing and Zhangjiakou areas.The seed shattering rates of H.brevisubulatumafter 16 days of full flowering in Beijing for five continuous weeks were 12%,26%,53%,78% and 92%,respectively.The seed shattering rates of H.bogdanii after 16 days of full floweringin Beijing for five consecutive weeks were 8%,21%,58%,75% and 89%,respectively.The seed shattering rate of H.brevisubulatum after 16 days of full flowering in Zhangjiakou for five consecutive weeks were 5%,15%,46%,68%,88%,and that of H.bogdanii after 16 days of full flowering for five consecutive weeks were 11%,24%,49%,64%,and85%,respectively.Therefore,these two species shattered earlier and higher in Beijing than in Zhangjiakou,and the shattering rates for the H.bogdanii and H.brevisubulatum were the highest in the third week.The seed setting rates of H.bogdanii and H.brevisubulatum weresignificantly correlated with pollen activity and stigma receptivity,but the shattering rates were not significantly correlated with seed setting rate,pollen activity and stigma receptivity.