Early Study Of Progeny Test In The Third Seed Orchard Of Chinese Fir

The genetic improvement of Chinese fir(Cunninghamia lanceolata)is the key to promote the construction of Chinese fir fast-grown forest.After more than half a century of efforts of scientific research workers,Chinese fir breeding and improvement has entered the third generation of seed orchard breeding generation,but as one of the important production areas of Chinese fir in Sichuan,its fine seed level is only at the generation level of 1.5 generations.This study through the introduction of Fujian third-generation seed orchard family in Sichuan province to carry out the determination of genetic test,observation of the third generation of seed orchard family adaptability and growth status in sichuan,the determination of the differences between the various departments as well as the determination of genetic analysis,at the same time,the feasibility of early selection and reliability analysis,in order to based on the modified fir in the breeding work in Sichuan.The study results are as follows:(1)Growth characteristics of variance analysis showed that the introduction of family half compatriots offspring of tree height,DBH and V system achieves very significant differences at home in three years in the line of the introduction of 62,the average tree height,DBH and V of the respectively is 336.3 cm,4.18 cm and 3.38×10-3 m3;The variation coefficient of 9.2%,16.0% and 34.3% respectively.There were 37 families,30 families and 29 families that were larger than the population average.There were 9families of Chinese fir,10 families of DBH and volume bigger than that of Chinese fir.Among them,three indexes of 21,5,61,65,12,44 and 6 families were all larger than local Chinese fir.Different years of growth traits at home system differences were very significant level,both in the third year of the growth of Chinese fir were significant difference between the at home.(2)Genetic analysis of growth traits: the heritability of each trait was between 66.91% and78.40% in the first year after introduction,and remained between 66.23% and 68.27%in the third year,among which the heritability of a single plant showed a downward trend.Genetic gain 1 appeared to decline,the genetic gain 2 roughly showed a trend of rising,the genetic variation coefficients showed a trend of decline.The results showed that the overall growth of introduced Chinese fir families tended to be stable,and the influence of environment on the growth of Chinese fir was gradually reduced.Although only a small number of families exceeded the local Chinese fir at present,many families still had the potential to exceed the local Chinese fir in the later growth.(3)The analysis of variance of canopy breadth,height ratio and diameter ratio of Chinese fir trees confirmed the extremely significant difference between families,and the heritability of Chinese fir trees decreased from 69.91% of annual growth to 34.62% of three-year growth.Crown height and crown diameter ratio of the heritability remain at around 50%,it is still under certain genetic force control;Branches round round number and spacing of the method of variance analysis of the same system at home and keep the real differences between wheel spacing greater influence on the environment,family heritability is only 34.53%.Preliminary to distinguish the two types of coronary,determine the sparse degree has the real differences between branches wheel.The morphological indexes of genetic gain no obvious trend,the introduction of Chinese fir form is greatly influenced by the environment,on Chinese fir growth response needs further analysis.(4)the results of correlation analysis and principal component analysis showed that there was an extremely significant correlation between growth traits and morphological traits,indicating that morphological traits were closely related to growth of China fir.Using principal component analysis to its classification tower fir family grow better than umbrella family,tower sparse slightly better than tower type thick.In this experiment,we found that the growth is better than that of umbrella tower fir cunninghamia lanceolata,and the crown the bigger the sparse family relative to the crown of the small and densely populated with a narrow margin.Can guide us in the early selection of excellent Chinese fir family makes a preliminary judgment.(5)The results of photosynthetic physiology and stoichiometry showed that there were significant differences in chlorophyll content,apparent quantum efficiency,photosynthetic rate and other photosynthetic performance indexes among the tested families,while the differences among the other families were small.Family is small,nitrogen content differences between unit mass of nitrogen content is between 3.0 3.4mg/g,p content per unit area is between 3.4 ~ 3.7 mg/g.Different family phosphorus and nitrogen and phosphorus ratio difference is bigger,the unit quality phosphorus content is between 0.28 ~ 0.35 mg/g,7 were family nitrogen and phosphorus ratio range between 9.4 to 11.3,which showed that introduction of cunninghamia lanceolata growth is limited by nitrogen.The growth characters of imported families were significantly correlated with nitrogen and photosynthetic rate,so photosynthesis was restricted by nitrogen,which affected the growth of Chinese fir.For considering speed by nature,adaptability and stability properties of Chinese fir family choose to verify the feasibility of early selection.To sum up,there were significant differences in the growth characters of the half-sibling descendant families of the third generation seed orchard introduced from Fujian province in Sichuan.Under the control of large heredity,the growth trend tended to be stable year by year and had the growth potential to surpass the local Chinese fir families.Morphological characters also there exists a significant difference between each department,under the influence of some environmental factors such as light,temperature lead to hereditary floating around 50%,but still under certain genetic control.Physiological and ecological index verify the adaptability of introduction of family in the local comprehensive growth,differences between morphological characters can verify the feasibility of the introduction of family in the local and reliability.For the introduction of varieties on the family's early selection and Sichuan province provides a theoretical basis for genetic improvement of fir.