Studies On The Heterosis Of Alfalfa By SRAP Markers

In this paper,experimental materials were 31 alfalfa plants as parents and their 15 F1 hybrids,we analysed the genetic diversity of the parents,the genetic relationship and heterosis between parents and F1 hybrids using agronomical,morphological and molecular markers including SRAP methods.Then the accuracy of forecasting heterosis by genetic distance based on molecular markers.Then main results showed as follow:1. The clustering analysis on morphological indicated that 31 alfalfa plants could be divided into two groups.All of alfalfa plants (Medicago sativa L.) and four of alfalfa plants (Medicago falcata L.) were clustered into the first group;The other four of alfalfa plants (Medicago falcata L.) were clustered into the second group.The first group included two parts.Most of high and low fall dormancy alfalfa plants (Medicago sativa L. ) from abroad and internal belonged to different parts. A small part of high and low fall dormancy alfalfa plants (Medicago sativa L. ) belonged to the one part.The clustering analysis on SRAP indicated the results were similar to the clustering analysis on morphological, most of high fall dormancy alfalfa plants (Medicago sativa L. ) from abroad belonged to one part.2. 99 SRAP primer pairs showed that new bands different from both parents.The specific site of primer Me2—Em6 and F7—Em3 be related to plant height,plant width,stem length,node number. The specific site of primer F18—Em1,Me4—Em2,F12—R9 be related to leaf length,perimeter,leaf area and internode length. The specific site of primer F12—R15 be related to stem length and node number. The specific site of primer Me4—Em2,F13—Em2,F13—R8 be related to shape of leaf factor. The specific site of primer F18—Em1,F13—R8 be related to branch number and biomass.3. Analysis on correlation between the mid-parent heterosis of bionmass and morphological triats for 15 F1 hybrids and genetic distance with SRAP molecular markers.It is indicated that heteroses exist, and molecular markers can be used to predict heterosis in this experiment.