Studies On Seed Germination And Phenotypic Characteristic Of Achnatherum Inebrians Under Different Habitat In Xinjiang

The overflowing of poisonous and harmful grasses was caused rapid deterioration of pasture ecological environment, which seriously affected the development of local animal husbandry and incomes of farming herdsman, and accelerated further degradation of pasture, hence prevention and control of poisonous and harmful grasses in pasture was necessary. It was important that population propagation mechanism of poisonous and harmful grasses under natural condition was understood for its prevention and control. Achnatherum inebrians was the main pasture poisonous weed in north slopes of Tianshan Mountain, Xinjiang. In order to reveal A. inebrians population propagation mechanism, and to provide the basic for its control and utilization, two experiments was carried out, namely,(1) the effect on A. inebrians seeds germination characteristics of different habitat under different germination condition such as temperature, light, water, was studied by using the routine paper bed culture,(2) the effect on its phenotypic characteristic sunch as height, herbosa diameter, tiller number, modular biomass, under different habitat condition was studied by using the routine field sampling method. The mainly results were as the follows:(1) There was a certain difference on germination rate, germination energy, germination index, radicle length and germ length of A. inebrians among different habitat in Xinjiang. Compared with full light condition, the germination rate, germination energy, germination index and radicle length of four A. inebrians were significantly improved under dark condition at constant temperature(P<0.05), and the best was at 25 ℃, the average germination rate, germination energy and germination index was 92.3%, 73.6% and 8.2 respectively. Whenever lighting or not, the germination rate, germination index, radicle length and germ length of four A. inebrians under 20 ℃/10 ℃ condition was better than that of 20 ℃/5 ℃(P<0.05). With the increase of the elevation, germination rate, germination energy and germination index of A. inebrians were significantly descreased, but radicle length and germ length were no significantly correlation(P>0.05).(2) The germination rate of A. inebrians was improved under low PEG concentration from 5% to 10%, the germination energy, germination index, vitality index and germ length of A. inebrians were decreased under high PEG concentration of 15%, but the radical length was increased. There was significant difference on germination rate, germination energy, germination index of different A. inebrians under PEG stress(P<0.05), and its drought resistance of low-middle elevation from 1650 m to 1832 m was higher than that of high elevation of 2287 m.(3) With the increase of the elevation, the fertile tillers number, flowers or fruits weight and height of A. inebrians were deiscreased. There were no significant difference on underground biomass and root length of A. inebrians among different habitat, was repectively 37.5 g/individual ~ 92.1 g/individual, 6.6 cm~7.9 cm. Aboveground biomass of A4 was higher than that of A5 and A6 in June, but in July A5 was higher than that of A4 and A6(P<0.05). There was significant difference on long axis length, short axis length and crown width area of A. inebrians among different habitat only in July(P<0.05), and A5 was lower than A4 and A6(P<0.05).(4) As far as aboveground modular biomass of A. inebrians concered, there was no significant difference on stem weight in June and leaves weight in July among different habitat(P>0.05), but leaves weight of A4 was higher than that of A5 and A6 in June, and in July stem weight of A5 was higher than that of A6 and A4(P<0.05). The flowers or fruits weight of A. inebrians in low elevation was significant higher than that of high elevation(P<0.05). The sequence of biomass allocation of A. inebrians from high to low was the leave, stem and flower or fruit, the proportion was respectively 48.2% ~ 80.2%, 13.5% ~ 30.0%, 0.7% ~ 21.8%,and which had different among different habitat. Stems biomass allocation proportion of A5 was higher than that of A6 and A4 in July(P<0.05), leaves biomass allocation proportion of A6 and A4 was significient higher than that of A5(P<0.05), and flowers or fruits biomass allocation proportion of A5 and A6 was higher than that of A4 in June and July.