Study On Germplasm Resource Evaluation And Selection Of The Superior Clones For Local Late-Maturing Walnut Of Mabian County In Sichuan

In this study, we use the local Late-Maturing walnut of Mabian county and the as the experimental materials. Walnut germplasm resources survey, including origin conditions (lacation, the household names, habitat, tree age, operation and management), growth conditions (tree vigor, tree stance, tree shape, tree height, crown width, branch height, diameter at breast height), leaf and fruit characteristics, phenophase(flowering & fruiting, flower and fruit drop period), seed status (fruiting branches rate, production situation, fallen fruit circumstances, nuts shape,nuts size, kernel color), has been made in Mabian County. Given that, morphometric indicators (nut high,abdominal diameter, DBH, nut weight, shell thickness, shelling rate) and seeds inclusions (crude fat, crude protein) have been measured and analyzed after repeat survey and sampling. And according to the different use of target selection of walnut. In order to evaluate the germplasm resources and select the good clones. For this purpose, We studied the walnut germplasm resources survey, including death rate, male flowers rate, growth conditions,resistance to diseases and pests.Based on this, we evaluated the nuts quality, including:nut high,abdominal diameter, nut weight, shell thickness, shelling rate) and seeds inclusions (crude fat, crude protein) have been measured and analyzed. A germplasm nursery has been established for Teaching and Research Base of Sichuan Agricultural University in Chongzhou,and plus trees have been grafted propagation. After observing walnut early traits and evaluation, the conclusions are as follows:(1) The local Late-Maturing walnut is better than the Xiang-ling in adapting to the Western sichuan plain climate. In the third year of planting, the death rate of Xiang-ling is 72.6%,and far more than this indicator in the local,which is just 22%;the male flowers rate, Xiang-ling is 11%,which is almost 1/4 of locals; the locals are grow faster and strong than Xiang-ling, specific in Ground diameter the crown and tree height; for the resistance of Plant diseases and insect pests, the local walnut has a great advantage.(2) Local Late-Maturing walnut grow fast and strong, the ground diameter, crown breadth, plant height were good, show good flowering and at the same time, a strong resistance to leaf spot and insects. In later walnut selection and promotion, more growth of local night real walnut, can increase the income of forest, reduce risk.(3) Local Late-Maturing walnut variation is very rich, can be used as a rich germplasm resource walnut breeding research. Walnut form in Local Late-Maturing walnut is usually round, a few oval, the fruit high is 2.4cm～4.7cm, fruit diameter is 2.4cm～4cm, fruit weight is 3g to 17.9g, shell thickness is0.4mm～2.5mm, the kernel rate is 24.9%～ 73.6%, the fat content is 26.7%～67.7%, and the protein content is 12.7%～19.3%.(4) According to death rate、male flowers rate、growth and he resistance of Plant diseases and insect pests, we selected 15 local Late-Maturing walnut as the candidate clones. At last, we selected five good local Late-Maturing walnut clones of Mabian county the clone Serial number are:33、64、70、138、171。...