| Black locust (Robinia pseudoacacia), as a woody feed,with high crude protein of dry matter content of leaf and high utilization, is part of the solution to the development of the livestock industry for the shortage of protein feed and feed energy shortage problems.To save for food and solve conflicts for food between people and livestock, the development of saving animal husbandry has a very important role. Black locust is one of the most closely trees in the restructuring of the plantation industry and ecological environment construction silvipasture too. Based Hungary polyploid clones, Korea tetraploid, long leaf locust and yu 1 black locust ,we made a feed-locust screening and drought-tolerance test. In the feed-locust screening experiment,we made mensuration to four planted in 2004 clones in different years and different month at the crude protein content in comparison. In drought-tolerance test, based a -year-old potted and grafted seedlings , through natural drought, we mensurated the physiological and biochemical changes of four clones in natural drought stress .at the same time,we used inFuzzy math and the method to analyse. Determination of these indicators includes tree height, diameter, photosynthetic rate, transpiration rate, SOD, POD, CAT, MDA, RWC leaves, leaf chlorophyll content, lipid membrane permeability, soluble protein content, soluble sugar content, proline content of 14 indicators. The results showed :(1) long-leaf Locust has the highest crude protein content among the Clones. Its average crude protein content of leaves is 23.85%, outgoing Yu1locust, Korea tetraploid, Hungary polyploid Locust at 39.66%, 17.57%,7.90%. Leaf crude protein content of Locust in different year and different season has large difference among the clones.In comparison , performance of Hungary polyploid Locust is relatively stable,long-leaf Locust has middling changes, and Korea tetraploid has the biggest changes.(2) The locust clones of photosynthetic rate reduces with the strengthening of drought stress in general. on the frist day, diurnal changes of four locust clones are in the same general trend, with a clear photosynthetic "morning" phenomenon and Around 10:30 in the morning to a maximum. To the ninth day, all clones photosynthetic rate generally reduces to a low level, which are referred to peak at around 8:30.(3) With the decline in soil moisture, transpiration rate is overall in downward trend in drought stress, having obvious diurnal variation. On the Frist Day, Yu 1 locust clones and Korea tetraploid unimodal peak at 10:30 and 12:30, Other Clones radiate bimodal type. the transpiration rates of the individual moment on the fifth day are less than ones on the ninth day, but on the whole the transpiration rates is greater than ones on the ninth day.(4) Locust clones under drought stress can mobilize to remove the protective enzyme activity in vivo oxygen, to protect the cell membrane from the ROS attack. But different clones under drought stress have different responses. Korea tetraploid major mobilizes POD, Hungary polyploid major mobilizes SOD, CAT enzyme and long-leaf Locust major mobilize POD and CAT enzyme ,yu 1 Locust major mobilize SOD to remove reactive oxygen species. This shows there is the difference between tetraploid (polyploidy) and diploid locust Robinia pseudoacacia and the former has not the main reunification protective enzyme. Under self-control and interaction among SOD, POD and CAT enzyme, MDA content of different clones has different dynamics change.(5) Under the persistent drought conditions the growth of the black locust clones will be affected due to water stress, But different species have vary affected degrees . Under drought stress Yu 1 locust clones has the most Drive Growth and Korea tetraploid has the most height growth.(6) soluble protein and soluble sugar content of Locust Clones are accumulated with the strengthening of drought stress.This adaptation is positive implication under arid environment. Clones Hungary polyploid and long-leaf Locust which have high soluble protein and soluble sugar content have strong resistance to drought stress. Under drought stress leaf membrane permeability of the overall locust Clones increase and lipid peroxidation strongthen.this shows Locust cell membrane is injuried by drought stress, but the Clones have vary injuried degrees, of which long-leaf Clones is hurt in the lightest degree.(7) Leaf chlorophyll content and relative water content of locust clones are in overall in a downward trend with the decline of soil water content. But under drought stress, the declines has the vary magnitude among the clones. The relationship between Photosynthesis and chlorophyll content is quite complex, not simple positive correlation or negative correlation. Under drought stress for the majority of clones, photosynthetic rate is not directly caused by the chlorophyll content.(8) In the process of drought stress, proline content of the locust clones is in basically the same trend. From the first day to the fourth day proline content has not very noticeable change. From the fourth day to the seventh day proline content is in a rapid rise, but the increases among the clones are different. From the seventh day to the tenth day because of strengthening of drought stress, Yu 1 locust and Korea tetraploid clones began to be in a downward trend.(9) Locust's drought resistance is the complex genetic traits which are controled by many morphological and physiological and biochemical characteristics . itis difficult to accurately reflect the plant's ability to adapt to drought Using a single drought indicators to identify it. sometimes there are great discrepancies. Under drought stress through analysing the 14 physiological and biochemical indicators , we can know Hungary polyploid and long-leaf Clones have high drought resistance and Yu1 locust and Korea tetraploid clones have weaker drought resistance. Using fuzzy math to Comprehensively Evaluate it we can know that the order of drought resistance of the four locust clones is: Hungary polyploid >long-leaf Locust> yu 1 Locust> Korea tetraploid. By comparison, the indicators of soluble sugar and soluble protein and lipid membrane permeability have the most direct reflection to its drought resistance.(10) From the crude protein content and drought-tolerance assessment we can know : long-leaf and Hungary polyploid Locust is better feed drought-locust, compared to yu 1 Locust and Korea tetraploid.
|
PDF Full Text Request