青海草地早熟禾耐寒性研究

STUDY ON COLD TOLERANCE OF POA PRATENSIS L. GRASSLAND IN QINGHAI

青海草地早熟禾(Poa pratensis L.)可通过一系列生理反应提高越冬时的抗寒能力,如以较高的束缚水含量、较低的电解质外渗率和丙二醛(MDA)含量、增加脯氨酸和可溶性糖积累量等抵御严寒。(1)青海草地早熟禾的束缚水含量达到18.9%,显著高于引进品种,表明其通过提高束缚水含量避免细胞内外结冰来抵御寒冷。(2)青海草地早熟禾的电解质外渗率和丙二醛(MDA)含量显著低于引进品种,表明对低温导致的伤害具有较大抗御性。(3)秋末气温下降过程中,草地早熟禾叶片、根、分蘖节中的脯氨酸、可溶性糖积累显著。整体上,青海草地早熟禾脯氨酸和可溶性糖含量均高于引进的纳苏品种,但可溶性蛋白含量与引进纳苏品种无显著差异。

The cold resistance of Poa pratensis L.Qinghai could be increased by its own series of physiological modulation. With the decline of temperature.(1) Bound water content of V-QH was 18.9%,which was significant higher than those I-NS. The results indicated that V-QH could avoid icing inside and outside cell by advancing the bound water content.(2) The electrolyte leakage and MDA content of V-QH were under than those of I-NS.(3) With the drop of temperature in autumn,there were significant accumulations of soluble sugar and free proline contents in leaf,root and tillers among Poa pratensis L. Soluble sugar and free proline contents of V-QH were higher than those ofl-NS,however,soluble protein contents in both varieties were not significantly different.