Response and adaptation to the accumulation and distribution of photosynthetic product in peanut under salt stress

To clarify the response and adaptability of peanut under salt stress,Huayu 25 was used as the material,and non-salt stress(CK),0.15% salt stress(S1),and 0.3% salt stress(S2) were applied as three treatments.The study analysed the effects of salt stress on photosynthetic characteristics,photosynthetic substances accumulation and distribution as well as the ecological adaptability of peanuts.The results showed that net photosynthetic rate(Pn),SPAD value,leaf area,and peanut yield were reduced under salt stress.Pn in CK was 13.71 and 28.72% higher than that in S1 and S2 at the 50 th day after planting,respectively.At the same growth period,the SPAD value among treatments was ranked as follows: CK>S1>S2.The 100-pod mass,100-kernel mass,kernel rate to pod,and pod mass per plant were reduced under salt stress,and the trend was CK>S1>S2.The distribution proportion of dry matter in different organs of peanut plant was changed to adapt to such stress.Roots under salt stress intensively distributed in a 0-40 cm soil layer for salt resistance.Dry mass proportion in stems and pods increased during the vegetative stage and early period of reproductive stage,respectively.The maximum growth rates of the pod volume,pod dry weight,and seed kernel dry weight all declined,and the pod and kernel volume at harvest were reduced,improving the seed plumpness under salt stress.This finding could be useful in growing peanut in saline soil.

Genetic dissection of the grain-filling rate and related traits through linkage analysis and genome-wide association study in bread wheat

Wheat grain yield is generally sink-limited during grain filling.The grain-filling rate(GFR)plays a vital role but is poorly studied due to the difficulty of phenotype surveys.This study explored the grain-filling traits in a recombinant inbred population and wheat collection using two highly saturated genetic maps for linkage analysis and genome-wide association study(GWAS).Seventeen stable additive quantitative trait loci(QTLs)were identified on chromosomes 1B,4B,and 5A.The linkage interval between IWB19555 and IWB56078 showed pleiotropic effects on GFR_(1),GFR_(max),kernel length(KL),kernel width(KW),kernel thickness(KT),and thousand kernel weight(TKW),with the phenotypic variation explained(PVE)ranging from 13.38%(KW)to 33.69%(TKW).198 significant marker-trait associations(MTAs)were distributed across most chromosomes except for 3D and 4D.The major associated sites for GFR included IWB44469(11.27%),IWB8156(12.56%)and IWB24812(14.46%).Linkage analysis suggested that IWB35850,identified through GWAS,was located in approximately the same region as QGFR_(max)2B.3-11,where two high-confidence candidate genes were present.Two important grain weight(GW)-related QTLs colocalized with grain-filling QTLs.The findings contribute to understanding the genetic architecture of the GFR and provide a basic approach to predict candidate genes for grain yield trait QTLs.