Genetic Analysis And QTL Mapping On The Forage Yield Related Traits In Forage Triticale Based On The RIL Population

The shortage of high quality forage hinders the development of animal husbandry to some extent.To find high quality and high yield forage is one of the ways to solve this contradiction.As one of the premium forages,higher forage yield is one of the breeding objectives for triticale.However,in practice,it is aimless and labor intensive to select and breed triticale varieties based on phenotypes.Plant height,tiller number,flag leaf width,flag leaf length,under-ear internode length and fresh weight per plant are important traits correlated with forage yield of triticale.To construct the theoretical foundation of effective selection,molecular mark assisted breeding and gene mining of the forage yield correlated traits in triticale,273 individual plants from forage triticale population RIL were selected in this study as the materials to determine the in-field phenotype indexes such as plant height,tiller number,flag leaf width,flag leaf length,under-ear internode length and fresh weight per plant,combined with the molecular map of triticale RIL population constructed by our research team,the genetic mechanism of triticale forage yield was analyzed,which provided a research basis for the genetic improvement of triticale high yield.The results were as follow.(1)Among all the traits in RIL population were as follows: fresh weight per plant(64.10%),tiller number(45.05%),internode length under ear(34.29%),plant height(14.85%),flag leaf length(10.59%)and flag leaf width(9.68%)in descending order.The phenotypic distribution of yield traits in RIL population showed the feature of transgressive inheritance.The correlation coefficients of triticale forage yield and fresh weight per plant were permuted as under-ear internode < flag leaf length < plant height < flag leaf width < length tiller number in ascending order.Complex correlativity was obtained among traits,tiller number was negatively correlated with plant height and under-ear internode length,plant height was positively correlated with under-ear internode length,flag leaf width was negatively correlated with under-ear internode length.By applying principal component analysis,traits correlated with forage yield could be categorized as biomass component and plant height component which had a cumulative contribution rate of 70.81% and could practically reflect the comprehensive information of forage yield traits in triticale.(2)A total of 16 QTL loci for forage yield traits(plant height,tiller number,under-ear internode length and fresh weight per plant)with large variation in RIL population were detected on7 linkage groups.5 QTLs related to plant height,4 QTLs related to tiller number,3 QTLs related to under-ear internode length and 4 QTLs related to fresh weight per plant were detected.In this study,a total of 273 RIL populations composed of two forage triticale hybrids were used to synthesise forage yield related traits into biomass components and plant height components by principal component analysis.Combined with the population molecular map of triticale,a total of 16 QTL loci related to forage yield traits were detected based on this map.Based on these results,a total of 16 QTL loci related to forage yield traits were detected.