Development And Utilization Of Soybean First Pod Height Marker

The First Pod height is one of the important agronomic traits of soybean,and it is an important form of soybean large-scale mechanical production and one of the important indirect factors for affecting soybean yield.In recent years,the contradiction between supply and demand of soybean in China has become increasingly prominent,forcing the soybean industry to develop rapidly.Mechanized production is an important guarantee for the efficient development of the soybean industry.Mechanical harvesting is the central link of mechanized production,due to the habit of soybean falling and frying,the loss of soybean machinery harvest is high.how to reduce mechanical losses of soybean harvesting process has been a major problem in the study of soybean yield.With the development of agricultural mechanization,the importance of the first pod height is more obvious,and the breeders pay attention to the first pod height gradually.The trait of the first pod height has also become one of the basis for measuring whether soybean varieties are suitable for mechanized harvesting and whether they can be widely promoted.Breeding excellent varieties of soybean suitable for mechanical harvesting has become an urgent need for breeders.The heritability of the first pod height is higher,and by improving the population,so that the first pod height of soybean is increased appropriately,the number of grains in the upper part of the stem is increased,and the mechanical harvest is reduced,and the production loss is reduced.Therefore,directed genetic selection of the first pod height is an important way to breed soybean varieties suitable for mechanized harvesting.In this study,the recombinant inbred line?RIL?population was selected as the research material,the stability of light,temperature and water on the first pod height traits of the population were analyzed,and the traits were predicted by genetic model,the QTL mapping and epistasis of RIL were studied.By QTL mapping analysis with 11 major QTLs were obtained,Marker-assisted selection?MAS?of RIL population and Chromosome Segment Substitution Lines?CSSLs?were carried out by using markers closely linked to QTL.The superior resources with significant difference on the first pod height were excavated to provide theoretical basis and material preparation for breeding new soybean varieties suitable for mechanized harvesting.The results are as follows:1.Effects of different environmental factors on the first pod height of soybeanIn order to study the stability of the first pod height traits during different years,the meteorological data of Harbin City from May to September were reviewed.Meteorological data including average precipitation,sunshine hours,temperature,etc.,after correlation analysis,it was not significantly correlated at the 0.05 level.Therefore,single meteorological factors have little effect on the first pod height of soybean.The average pod height of soybean in 2008,2009 and2013 was significantly different from that of other years by multiple comparative analysis of 8years'experimental data.In addition,the average data for 2006 and 2007 are not significantly different from the 2010 data;the 2006 average data is not significantly different from the 2007data;the 2014 average data is not significantly different from the 2015 data.Therefore,it is preliminarily concluded that the height of soybean pods is less affected by a single meteorological factor,but it is greatly affected by meteorological factors.2.Heritability and genetic model analysis of the first pod heightIn this study,the generalized heritability H² of the pod height was 0.6363,indicating that in the offspring population,63.63%of the phenotypic variation of soybean pod height traits was determined by genetic factors,while environmental factors determined 36.37%of the variation.The phenotypic mean of the 8-year pod height trait of the RIL population was analyzed using the quantitative trait separation analysis software?SEgregation Analysis-DH?.Calculate the AIC?Akaike's information criterion?value according to the likelihood function value of the model.According to the principle of minimum AIC value,the model with the smallest AIC value is the relatively best model.Therefore,this study selects the 0MG model,which is the pod-free trait-free gene,which is controlled by multiple genes.3.Genetic analysis and marker development of soybean pod heightQTL analysis of the RIL population using the CIM model of Windows QTL Cartographer ver.2.5,From 2006 to 2015?except 2011 and 2012?,11 QTLs related to FPH were detected.Four,three,one,one,one,and one QTL were detected on the linkage groups D1b,D2,I,L,M,and J,respectively.The epistatic effect analysis of the 8-year first pod height data were performed using IciMapping software.90 pairs of epistatic effect sites were obtained in 5 years,and 32 pairs,2pairs,1 pair,42 pairs and 13 pairs were detected in 2006,2007,2008,2009 and 2015,respectively.Among the 90 pairs of epistatic QTLs,there are 3 pairs of epistasis effects between the major loci?the main loci on M,D1b and D2 linkage groups in 2006,2009 and 2015,respectively?.PVE was1.07%,1.33%and 2.46%,respectively.In addition,there are 12 pairs of sites between the main site and the non-principal site,and their PVE is 1.08%-16.66%.The remaining sites are present between the non-primary sites and their PVE is 0.61%-11.93%.A total of 29 pairs of tags distributed on 6 linkge groups were obtained for the next step to assist in the marking selection of excellent materials.4.Marker utilization of first pod height traitsUsing the 11 QTL linkage genetic markers obtained by location,147 RIL populations were tagged for pre-planting screening to predict possible high and low values of materials,and the height of pods selected by the autumn post-harvest survey.Combined with the performance of the phenotype in other years,two RIL materials with high height of pods were screened,namely RIL-86 and RIL-101,and three RIL materials with low height of pods were screened,respectively,RIL-141,RIL-2 and RIL-112.Using 29 pairs of SSR marks,13 pairs of parents with difference SSR marks were used to mark the selection of imported offspring in the spring.After the autumn harvest,a phenotype data survey was conducted to analyze the effect of assisted selection.Among them,BARCSOYSSR₁6₀783,BARCSOYSSR₁6₀783,BARCSOYSSR₁6₀832 on chromosome16 and BARCSOYSSR₀832 on chromosome 17 and BARCSOYSSR₁70948 and BARCSOYSSR₀916 on chromosome 16 were extremely prominent in the CSSL group,and chose the obvious effect.The other 8 pairs of primers have a normal selection effect.For the CSSL screening,11 excellent materials were obtained,of which 6 were high value materials and 5 were low value materials.The high height material was about twice as high as the height of the low height material.Among them,the height of the pod of the high pod material is18.91 cm-41.60 cm,and the height of the low pod height material is 9.42 cm-11.84 cm.The height of the CSSL-1760 pod is up to 41.60 cm,and the height of the CSSL-695 pod is as low as 9.42 cm.Through mark-assisted selection,the selection of highly specific materials for pods can be achieved quickly,and the screening results are more reliable.