Study On Production Performance And Analysis Of F₂ Hybird Progenies By Molecular Markers And Morphological Characteristcs In Annual Ryegrass (Lolium Multiflorum)

Six parental cultivars of lolium multiflorum and eighty F2 progenies of nine cross combinations were used in this study. SRAP and SSR markers were used to analyze genetic relationship of 86 lolium multiflorum accessions,and discussed molecular marker used in lolium multiflorum breeding.Thirteen morphological traits of eighty F2 hybrid progenies were meansured at heading stage and flowering period to analyze by analysis of variance. Analysis of simple correlation and principal component analysis, by which elite cross combinations and hybrid progenies were selected for further cross breeding. Besides, in order to assessmented adaptability, potential replication and breeding value of eight annual ryegrass cutivars or lines in Southwest China, depending on production perfomance, growing speed,morphological characteristics, two years comparison test of eight cutivars and lines were carried out.The results were as followed:(1) Compared with the eight cultivars, Florida 4N was the most excellent and stable on fresh and hay yield observed in two years, achieved 112326kg/hm2, 14478kg/hm2 in 2008 and achieved 106000kg/hm2,15936kg/hm2 in 2009. Florida 4N also was the most excellent on growth speed, reaching 1.35cm/d. According to plant height, leaf width and other vegetative characteristics, Chuannong No.1 perform better than others. By clustering analysis on morphological trait, Chuannong No.1 was best forage grass cultivar in this test.(2) SRAP and SSR markers were used for genetic analysis,15 and 16 primer pairs were selected, respectively.16.7 bands were amplified per primer pairs on average and percent of polymorphic bands was 68.88 in SRAP analysis. The average number of bands per primer pairs was 14.75 and percent of polymorphic bands was 58.05 by SSR markers. The conclusion of analyze by Clutering tree showed that progenies from the same F2 cross combination clustered together, except the combination ChangJiang No.2×Jumbo,the genetic distance from F2 progenies to male parent or femal parent was so approximate. Meanwhile, the reliablity of UPGMA dendrogram for Lolium multiflorum F2 progenies and parental cultivars by SRAP markers was higher than SSR.(3) Thirteen morphological traits of eighty hybrid F2 progenies from seven cross combinations were evaluated at heading stage and flowering period. And statistical analysis such as coeffcient of variation and variance analysis indicated that there were singificant differences in seven combinations. Coeffcient of variation varyed from 6% to 48%, among different traits, tiller number was the highest and height of plant was the lowest. Correlation analysis showed that vegetative charateristics were simple, there were significant positive correlationship among width and lenth of flag leaf and width and lenth of second leaf. Principal component analysis showed that the first five principal components variance accumulation contribution rate amounted to 70.527%, which reflected most information of the morphological traits of tested accessions. Finally, by clustering analysis, eighteen progenies as 8-1,4-1,8-3,1-5,6-7,8-7and so on were picked up for outstanding yield of lolium multiflorum F2 progenies.