温度和稃壳去除对甘肃野生草地早熟禾发芽特性和多胚苗频率的影响

Effects of temperature and glume status on germinationand polyembryonic seedling frequency in seven wildgermplasm of Kentucky bluegrass native to Gansu

摘要:

以7个甘肃野生草地早熟禾(Poa pratensis)种质为材料,研究了不同温度和是否除稃壳对草地早熟禾发芽和多胚苗频率的影响。结果显示,不同材料的发芽势、发芽率、二胚率、三胚率以及多胚率在不同温度以及除稃壳后表现均不相同。这表明草地早熟禾的发芽情况和多胚率因材料来源、萌发温度和种子状态的不同而异。综合分析表明,除肃南和秦州采集的种子外,适当降低萌发温度可显著提高其余野生草地早熟禾种质材料的发芽率,不同的是,清水和甘谷采集的种子在除稃壳后,提高幅度更大;多胚苗频率的变化不同于发芽率,其中陇南和甘谷采集的种子多胚苗频率不随温度和种子状态变化而改变,其余5个材料的多胚率均在去除稃壳后显著增加,材料之间的差异性为甘南和定西采集的种子在30℃达到最大,清水和肃南采集的种子25℃为最大值,而秦州采集的种子在20℃最大。由此可见,实际生产中若要提高草地早熟禾的多胚率,可以通过控制种子萌发温度和去除稃壳得以实现。然而,具体的草地早熟禾材料还需要提前进行试验才能确定适宜的萌发温度以及是否去除稃壳。

Abstract:

Effects of different temperature and glume on the germination and polyembryonic seedling frequency of seven wild germplasm of Kentucky bluegrass (Poa pratensis) originated from the wild grassland in Gansu were studied.The results showed that germination energy,germination rate,two embryo seedling frequency,three embryo seedling frequency and polyembryonic seedling frequency of different germplasm changed in response to different temperature and glume status.The comprehensive analysis showed that reduced temperature could significantly increase the germination rate for most wild germplasm of Kentucky bluegrass except the seeds collected from Sunan and Qinzhou.For the germplasm collected from Qingshui and Tianshui,the glume removal significantly increased seed germination.The polyembryonic seedling frequency of the seeds collected from Longnan and Tianshui did not change in response to temperature and glume status,while it increased significantly after glume removal in the other five germplasm.The optimum temperature for maximum seed germination differed among different germplasm,with the germplasm collected from Gannan and Dingxi reached the maximum at 30℃,the germplasm from Qingshui and Sunan at 25℃,and the germplasm from Qinzhou at 20℃.Our results showed that the enhanced polyembryonic seedling frequency of Kentucky bluegrass could be achieved by controlling seed germination temperature and glume removal,and the appropriate germination temperature and the requirement of glume removal for different Kentucky bluegrass germplasm need to be tested in advance.