遗传改良对杉木针叶和种实性状的影响

Effects of genetic improvement on traits of needle and cone of Cunninghamia lanceolata

关键词:  杉木, 遗传改良, 育种群体, 针叶, 种实

Key words:  Cunninghamia lanceolata(Chinese fir), genetic improvement, breeding population, needle, cone

摘要:

为揭示遗传改良对主要造林用材树种叶和种实性状的影响,阐明性状的变异趋势,该研究以杉木第4轮育种的精选树(改良群体)、四省五地的表型优树与古树(未改良群体)为对象,调查了218个无性系的针叶和种实性状指标,采用方差分析和多重对比方法研究遗传改良对杉木及不同类型杉木的表型差异,并通过相关性分析探究遗传改良对杉木针叶和球果部分表型性状的影响,以及利用主成分分析和聚类分析进行了分类。结果表明:(1)未改良群体的针叶长、针叶宽和出籽率分别比改良群体小13.28%、10.81%和33.90%,其他性状表现为未改良群体大于改良群体,差异在10.90%～27.03%之间。未改良群体球果长、球果宽和出籽率的变异系数,分别比改良群体大9.14%、12.73%和15.38%。(2)球果长、球果宽、苞鳞长和苞鳞宽4个性状,在未改良群体中仅有球果长和球果宽(0.931)、苞鳞长和苞鳞宽(0.622)之间呈极显著正相关,经遗传改良后,该4个性状两两之间均呈显著或极显著正相关。(3)四川雅安(SCYA)的球果长和球果宽的性状比改良群体大48.83%和53.26%,安徽黄山(AHHS)的百粒重比改良群体大16.92%。(4)遗传改良导致松张型球果的杉木比例降低,紧包型和反翘型球果的杉木比例增加。综上认为,杉木的遗传改良导致球果大小下降,改变了不同针叶和球果类型的比例,同时会改变针叶性状和种实性状的相关性,将为杉木种质资源评价和未来多目标育种提供依据。

Abstract:

To reveal the effects of genetic improvement on leaf and seed traits of major afforestation timber species, and to clarify the variation trend of traits, selected trees(improved population)of the fourth cycle of Chinese fir breeding and phenotypic superior trees and ancient trees(unimproved population)in four provinces and five regions were selected as the research objects. The needle and cone traits of 218 clones were investigated, and the study used variance analysis and multiple comparison methods to study the phenotypic differences of genetic improvement on Chinese fir and different types of Chinese fir. The correlation analysis was used to explored the effect of genetic improvement on the phenotypic traits of Chinese fir needles and cones; the principal component analysis and cluster analysis were used for classification. The results were as follows:(1)The needle length, needle width and seeding rate of the unimproved population were 13.28%, 10.81% and 33.90% smaller than those of the improved population, respectively. Other traits showed that the unimproved population was larger than the improved population, with differences ranging from 10.90% to 27.03%. The coefficients of variation of cone length, cone width and seeding rate of the unimproved population were 9.14%, 12.73% and 15.38% larger than those of the improved population, respectively.(2)Among the four traits of cone length, cone width, bract scale length and bract scale width, only cone length and cone width(0.931), bract scale length and bract scale width(0.622)were extremely significant positive correlation between them in the unimproved population. After genetic improvement, the four traits showed a significant or extremely significant positive correlation in pairs.(3)Cone length and cone width in Sichuan Ya'an(SCYA)were 48.83% and 53.26% larger than those in the improved population, and the hundred-grain weight in Anhui Huangshan(AHHS)was 16.92% larger than those in the improved population.(4)Genetic improvement led to a decrease in the proportion of Chinese fir with loose-stretched cones, and an increase in the proportion of Chinese fir with tightly packed and inverted cones. In summany, this study believes that the genetic improvement of Chinese fir leads to the reduction of cone size, changes the proportion of different needles and cone types, and changes the correlation between needle traits and cone traits, which will be helpful for providing the basis to the evaluation of Chinese fir germplasm resources and future multi-targets breeding.