Preliminary Study on Salt-Tolerant Mechanism of the New Pennisetum Purpereum Schumach Variety-Sumu No.2
|School||Nanjing Agricultural College|
|Keywords||sea-salt stress seeding stage Sumu No.2 physiological microstructure|
Purpureum Pennisetum Schumach was native to tropical African, it has a strong resistance, wide adaptability, highly photosynthetic efficiency, and can be used for the high quality green fodder for fish and herbivores, plant of water and soil conservation, raw materials of high quality pulp and man-made board, and it is important energy crops. Sumu No.2 is a new saline-variety of Purpureum Pennisetum Schumach which was authorized in 2010 by national. It used N51 for raw materials to get Purpureum Pennisetum Schumach of salt resistance by cell engineering screening out of somatic mutations. Seedling growth situation, morphological characteristics, cationic accumulation of different parts of plant and variation rules of antioxidative activity and MDA content of leaves were studied. It could provide technical support for the efficient and ecological using of saline soil and the industrial application of Sumu No.2 on the saline soils.The results are as follows:(1) The plant length, dry weight of different parts of plant of Sumu No.2 and N51 decreased and damage degree of leaf increased with the sea-salt concentration increased; Growth inhibitory gradually significant under different sea-salt concentration after prolonged sea-salt stress time. Under 4g/L,6g/L and 1 Og/L sea-salt concentration, the relative deied leaf rate and deied leaf DW rate of N51 were 1.27,1.25,1.09 and 1.44,1.20,1.15 times of Sumu No.2 after 28d treatment. The dry weight of SuMu 2 stem and fresh leavse was significantly higher than N51.(2) With sea-salt concentration increasing, Na+content increased and K+、Ca2+、Mg2+ content and K+/Na+ reduced in different parts of Sumu No.2 and N51 plants. Na+ content in different parts of Sumu No.2 and N51 plants was:leaf<stem<root,K+ content was: root<leaf<stem,K+/Na+ was:root<stem<leaf,Ca2+ content was:root<stem<leaf and Mg2+ content was:leaf<root<stem under the same sea-salt concentration stressed.Under 4～10g/L sea-salt concentration stressed, K+/Na+ of Sumu No.2 has not significant difference in roots with N51, higher than N51 in stems, significantly higher than N51 in leaves besides that Sumu No.2 and N51 have not significantly different under 4g/L treatment after 28d stressed; S K+/Na+ (stem/root) ability of Sumu No.2 were 1.02-2.19 times of N51 in addition to Sumu No.2 lower than N51 under 4g/L treatment after 7d stressed.(3) The results showed that SOD and POD activities of Sumu No.2 and N51 increased with the increasing of sea-salt concentration after 14d,21d and 28d of stressed, the content of MDA increased with sea-salt concentration increasing after 7d,14d and 28d of stressed and CAT activity had interactive effects between the stress of sea-salt concentration and time under the stress of 0～6g/L sea-salt concentration. The activity of SOD and POD of Sumu No.2 very significantly (P<0.01) higher than those of N51, CAT activity was significantly (P<0.01) higher than that of N51 except that 4g/L and 6g/L of sea-salt concentration after 7d stressed, MDA content was obviously (P<0.05) lower than those of N51 besides Og/L of sea-salt concentration after 28d stressed. Sumu No.2 and N51 were all dead under lOg/L sea-salt stressed in 21d.(4) Total density of stomatal and leaf hair and bulliform cell length of Sumu No.2 and N51 increased with the increasing of sea-salt concentration. Leaf total cross-sections per Vascular bundle number of Sumu No.2 decresed, N51was:0 g/L>6 g/L> 4 g/L> 10 g/L(6 g/L higher than 4 g/L for 6.98%) with the increasing of sea-salt concentration. Leaf total cross-sections per Vascular bundle number of Sumu No.2 lower than N51 except that higher than N51 for 13.69% under 4g/L of sea-salt concentration stressed; Bubbly cells length of Sumu No.2 lower than N51 under Og/L and 4g/L of sea-salt concentration stressed and higher than N51 under 6g/L and 10g/L of sea-salt concentration stressed; Stomatal total density of Sumu No.2 extremely higher than N51 except that lower than N51 under 0g/L of sea-salt concentration stressed.