The Research On Walnut Resources And Selective Breeding In The Northwest Of Hunan Province

Walnut is a kind of famous dry fruit and woody oil plant in the world, Walnut resources are abundant in Hunan province, but there are no improved variety resources of its own, and the effect is not so well by long-term introduction cultivation. In order to solve the problem about lacking of local variety resources in Hunan province, we carried out the research and selective breeding of walnut resources in northwestern of Hunan Province. This research adopted two kinds of methods, one was the combination of investigation and field survey, and the other was the combination of field investigation and indoor analysis methods, to conducted a walnut resoures investigation and determination in northwestern of Hunan Province, including Xiangxi, Huaihua, Zhangjiajie, Changde cities, especially in Sangzhi County, Cili County, Shimenn County County, Taoyuan County, Jingzhou County, Mayang County, Longshan County, etc. The main content of survey were the walnut resources distribution, habitat, production status, superior tree selection, selection of varieties. And the measurement of selected superior plants on phenotypic and economic traits of tree body, and flower traits. Nut phenotype and economic traits, fatty acid composition and physicochemical properties, mineral elements of walnut selected superior plants and hickory varieties were determined respectively. Through variance analysis, correlation analysis, principal component analysis, cluster analysis and other multivariate statistical methods, nut quality of Walnut selected superior plants and Hickory varieties were evaluated respectively. The main research results were as follows:1. Two cultivated walnut species distributed in the northwestern Hunan area were J.regia Z.and J.sigillata Dode., Three Hickory cultivated species were C. cathayensis Sarg, C.hunanensis Cheng et R.H.Chang,C. carya illinoensis (Wangenn.)K.Koch. J.regia Land J.sigillata Dode.had a long history and wide distribution in the northwest of Hunan Province, were distributed in every county in northwestern Hunan with sporadic distribution and blockbuster cultivation. Mainly distributed in Shimenn County, Cili County, Mayang County. Northwest of Hunan Province is one of the origin of the C.hunanensis Cheng et, which distributed in Jingzhou, Huitong,Yuanling, Fenghuang,Qianyang,HongJiang County, Jingzhou was the most concentrated, trees were aging without the seed selection for a long time. C.carya illinoensis (Wangenn.)K.Koch were has a small area by introduction cultivation, mainly planted in Huaihua, Mayang Jingzhou county. Only a small number of C. cathayensis Sarg planting, breeding in Jingzhou Dog Days Chong Park with an area of about 135 acres. Walnut habitat conditions are not the same in the northwestern Hunan, the production status mode of operation was different, diseases and insect pests were quite heavy, management level had good and bad, results also quite different.2.There were big difference on phenotypic and economic traits of tree body, flower traits, Nut phenotype and economic traits, fatty acid composition and physicochemical properties, mineral elements of Walnut selected superior plants,which indicated high genetic diversity, big breeding potential.The whole tree phenotypic traits were moderate variation, while crown areas was the largest among all. The transverse diameter, longitudinal diameter of the male flower, pedicel length is moderate variability, length of fruit stalk and fruit weight belonged to moderate variation, fruit stalk was the largest among all. Nuts of phenotypic traits in longitudinal diameter, height, width of suture were moderate variability, maximum height variation was suture. Shimen-2 nut shape was oval, the rest were oblong or round walnut. Kernel was 35.38%-71.78%, nuts weight was 7.25 g to 17.73 g, oil yielding rate was 49.45%-76.39%, shell thickness was 0.88 mm to 2.24 mm, soluble protein was 6.21 mg/g-8.18 mg/g. We detected five kinds of main fatty acid, which were palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid. Unsaturated fatty acid was not quite different between each other.5 oil physical and chemical properties, only the acid value of moderate variation, mineral elements, from high to low in turn is:N>K>P>>Ca> Mg>Mn> Cu> Zn. mineral elements were moderate variation except Mg, element. Zn was the highest.3. Correlation between the most optimal strain index reached significant or extremely significant level, the principal component analysis and comprehensive evaluation results showed that the nut quality had a better comprehensive performance were Shimen-2, Jingzhou-1-4, Shimen-3, Shimen-25, can be used as superior individual candidates.15 primary excellent individuals 13 nut quality indexes through cluster analysis can be divided into three categories. Class A nut called small fruit class, which includes Shimen-5 five excellent individuals, the class had high light nut, kernel, the characteristics of the thin shell; Class B called big fruit, nuts contain shimen-7, the two optimal JingZhou-1 strain, with nuts, shell thickness, but the characteristics of the kernel is low; Class C nuts for medium size, including eight strains, Shimen-1 hads the characteristics of the kernel is high, the spiral.4. Different hickory varieties in nut phenotype and economic characters, oil fatty acid and physical and chemical properties, had a larger variation nucleoli mineral elements. hunanensis nuts were different with the carya illinoensis, Each carya illinoensis had a better performance. Phenotypic traits for moderate variation, the diaphragm variation, the largest nut diameter variation is minimal. Nuts, economic characters of shell thickness, kernel, soluble protein, nuts were moderate variation, two are minimal. Five fatty acids composition were moderate variation. For pecan oil physical and chemical properties, the acid value and iodine value of moderate variation. Nucleolus of 17 pecans, determination of the content of 8 mineral elements, with all varieties of mineral elements content in average, from high to low in turn was: N>K>P>>Ca> Mg> Mn> Zn> Cu. Each type element content in the nucleolus mutations are moderate, coefficient of variation of maximum for Mn element content.5. The principal component analysis and comprehensive evaluation showed that the nut quality had a better comprehensive performance were 15 (Forkert),6 (Choctaw), 14 (Oconee), whost average nuts weighs 6.90 g, the average oil yielding rate was 60.27%, the average shell thickness of 0.62 mm, the average kernel is 60.00.%, the average oleic acid content is 70%, overall performance is significantly superior to all other varieties.14 to 17 varieties of pecan nuts quality index clustering analysis, divided into four classes, class A nut is lighter, spiral, the characteristics of high oleic acid; Class B has high soluble protein, the diaphragm thickness, high linoleic acid and linolenic acid high characteristic; Class C with high kernel, thin diaphragm is the heavier, nuts, and nut diameter big longitudinal diameter, nuts, low content of stearic acid, oleic acid, linoleic acid is higher, the characteristics of low linolenic acid; As a singular category, class D hunanensis all thickness, kernel low, low yield efficiency, soluble protein, the diaphragm thickness, large nuts, high stearic acid.