| Tartary buckwheat, rich in flavonoids, has the dual effect in diet and nutrition and health care, known as a important grain both in medicine and food industry. In recent years, there are many tartary buckwheat foods in super market. such as tartary buckwheat noodle, drinks, and function foods As tartary buckwheat cross breeding behind, most tartary buckwheat varieties on agricultural production are from selection breeding. Tartary buckwheat has thick shell, hindering the processing of tartary buckwheat live rice grains. On the basis of these problems, rice tartary buckwheat Xiao Mi Qiao with thin hells and tartary buckwheat Jin Qiao 2 with thick shells were crossed and their progenies(F2 and F3 populations, 245 RILs of F6) were studied on key agronomic traits and SSR molecular markers, in order to provide a theoretical basis for tartary buckwheat breeding and the processing for dehulling. The main results are as follows: 1. Analysis of main agronomic traitsGenetic variation of F2 and F3 population analysis showed that the ranges of phenotypic variation coefficient on yield factor for F2 and F3 were 40.03%~61.61,and 37.76%~51.21%, respectively. The ranges of genetic variation coefficient were 7.18%~62.10% and 5.94-69.37%, respectively.The analysis of heritability showed that grain number per plant has the biggest broad sense(0.764) and narrow sense heritability(0.709), the biggest in three yield related traits, followed by 1000 grain weight and the grain weight per plant. Among the other traits, plant height has the biggest heritability of broad sense(0.818) and narrow sense(0.562).Simple relation analysis showed that there were much significant positive relationship of grain weight per plant with plant height(r = 0.565 **), number of main inflorescence(r=0.338**), number of two bifurcations on main inflorescence(r = 0.464 **), number of grains per plant(r = 0.919**), and grain number on three top sprays(r=0.338**), and significant negative relationship with thin shell(r=-0.236**). There are much significant negative relationship of 1000 grain weight with grain number per plant(r=-0.452**). There are positive relationship of plant height with number of two bifurcations on main inflorescence(r = 0.464 **) and grain number per plant(r=0.507**). There are negative relationship of main branch number with 1000 grain weight(r =-0.125 *) and positive relationship with grain number per plant(r=0.360**)。The partial correlation showed that there are significant positive relationship of grain weight per plant with number of two bifurcations on main inflorescence(r = 0.135*), grain number on three top sprays(r = 0.136**), 1000 grain weight(r = 0.924**) and grain number per plant(r = 0.977**). There are significant negative relationship(r =-0.942**) between 1000-grain weight and grain number per plant. There are the negative relationship of plant height with number of main inflorescence(r =-0.303**), and positive relationship with number of two bifurcations on main inflorescence(r = 0.491**), 1000-grain weight(r = 0.223**), grain number per plant(r = 0.193**). There are positive relationship of main branch number with grain number on three top sprays(r = 0.145*), 1000 grain weight(r = 0.148*), and grain number per plant(r = 0.176**)。Regression analysis and path analysis indicated that 1000 grain weight had the biggest contribution to the grain weight per plant, followed by number of two bifurcations on main inflorescence, the smallest is grain number per plant. 1000 Grain weight has the biggest direct contribution to grain weight per plant. 2. SSR molecular marker analysisThere are 63 polymorphism primers screened from 576 primers and 80 SSR markers were discovered. Ici Mapping analysis showed that there are 18 markers with partial separation at 0.05 level, accounting for 22.5%. Among them, 15 markers are close to female parent.The maps including 12 linkage groups with total length of 1089.73 c M were established. Among them, linkage group LG4 has a longest map, LG1 has most SSR markers. 3. QTL analysis of key agronomic traitsIci Mapping complete interval method is used to analyze QTL loci. There are 25 QTL detected, they are, four QTL of plant height, three QTL of main branches, one QTL of number of two bifurcations on main inflorescence, one QTL of seed numbers on top main inflorescences, 2 QTL of grain number per plant, 5 QTL of grain weight per plant, and 6 QTL of shell thickness. There are two major genes(q PH1 for plant height by 11.13%, q YPP1 for grain weight per plant by 11.3%) detected. |
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