Study On The Biological Characters And Drought And Salt Resistance Of The Interspecific Hybrid F₁ Between Elymus Canadensis And E.sibiricus

The biological characters of the interspecific hybrid F₁ between E. canadensis and E. sibiricus were tested and analyzed by means of the powers method. Comprehensive evaluation of drought and salt resistance was conducted by subordinate function method. Based on the theory of grey correlation, the relationship between selective indexes of salt and drought resistance for the interspecific hybrid F₁ and related factors were analyzed. In addition, the grey order of factors affecting selective indexes of drought and salt resistance is determined. The main results as follows:(1)Turning green period of the interspecific hybrid F₁ were basically in accordance with its parents. The interspecific hybrid F₁ developed fast, growing and developing period was 139 days. The interspecific hybrid F₁ growth period depends on both parents. The mean heteroses in spike length was 1.6%. Spike shape of the interspecific hybrid F₁ is intermediate with the tendency to early parents which can be used as morphology marker to identify hybrid. Pollen fertility rate of the interspecific hybrid F₁ was 0.23%.(2)Leaf characters of the interspecific hybrid F₁ is intermediate with the tendency to early parents. The mean heteroses in leaf-length and leaf-area were higher than that in their parents respectively. The F₁ values of the tillers usually approach that of the low parents and its over-low parent.(3)The growth dynamics of the interspecific hybrid F₁ populution appeared in the form of a S-shaped curve, and the average growth rate was rapid at the booting stage and flowering stage, that is 2.89 cm/day. Regenerative ability of the interspecific hybrid F₁ was strong with 1-2 cuts within one year. The fresh grass yield (384.05 g·strains-1) was the highest in interspecific hybrid F₁ and the lowest (365.49 g·strains-1) in E. canadensis. The fresh grass yield of interspecific hybrid F₁ was 5.08% higher than that in E. canadensis.(4)The heterosis of the interspecific hybrid F₁ was stronger in crude protein, and over-high parent hetersis was 12.4%, but crude fiber content was significantly lower than their parents, and crude fat and soluble sugar were between E. canadensis and E. sibiricus.(5)The net photosynthesis rate and water use efficiency were of double-peak curves in the interspecific hybrid F₁ Leaves. When leaf transpiration rate was 1.5 mmol H2O?m-2?s-1, water use efficiency of the interspecific hybrid F₁was higher than that of their parents.(6)Drought and salt resistance of the interspecific hybrid F₁ decreased in the order of interspecific hybrid F₁ > their parents. There better indexes were selected. The indexes in order of decreasing influencing degree are the relative water content, proline, the chlorophyll content.