Hormone Regulation Mechanism Of Dwarf Strains And Phenotypic Effects Of Molecular Markers Related Plant Height In Peanut (Arachis Hypogaea L.)

Ideal plant type is an important goal of peanut breeding,and plant height is a key character that determines plant type.Plant height is closely related to yield,and is also the key to resist lodging and realize mechanized harvest breeding.Using ultra high performance liquid chromatography?UPLC?method,this study with 79266 and 04D893 hybrid strains of dwarf strains LA004,LA090,LA134 for material,in seedling stage of stem tip,a new leaf,third upper leaf,main stem four groups of auxin?IAA?,gibberellin?GA?and cytokinin?CTK?and abscisic acid?ABA?measurement,and applied GA₃ observed changes in plant height,internode,testing the response of the plant height of gibberellin,and then analyzes its agronomic characters,economic characters,variance analysis and its parent.In order to establish the physiological research foundation of hormone regulation mechanism of peanut dwarf strains and provide the theoretical basis for the identification and cultivation of dwarf peanut varieties.At the early stage,the QTL related plant height was detected between labeled HM171^ARS203 and co-isolated with labeled HM171,and the phenotypic effect was analyzed by determining the plant height traits of F₃ population.The main research results are as follows:1.Evaluation of agronomic traits of parent and dwarf strains.The main stem height and lateral branch length of the three dwarf strains LA004,LA090 and LA134 were significantly lower than that of the dwarf parent 04D893.The yield of LA004 is 13.55%higher than that of04D893.The yield of LA090 was 8.36%higher than that of 04D893.The pod yield of LA134was 29.38%higher than 04D893,and the yield was 2.08%and 22.66%higher than 79266 and04D893 respectively.The content of oil,stearic acid and LA090 linoleic acid and palmitic acid in the three dwarf lines were higher than that of their parents.The content of LA004 oleic acid was higher than 04D893 and linoleic acid was higher than 79266.The content of LA090 crude protein and total amino acid was higher than 04D893 and wascolic acid was higher than79266.The content of wascolic acid and palmitic acid in LA134 was higher than 79266.The three short stem lines showed good agronomic characters and seed nutrition components,and could be used as high quality germplasm for peanut plant breeding.2.The contents of endogenous hormones in different tissues of parent and dwarf strains were compared.The contents of Z?zeatin?,GA,IAA and ABA in different tissues of the three dwarf strains were significantly different from those of 79266 and 04D893,indicating that plant height dwarfing was not regulated by a single hormone,but the result of the coordination of multiple hormones.The contents of Z,GA and IAA in the newly developed leaves and main stems of 79266 and 04D893 were significantly higher than those in the dwarf lines,and the ABA content had little difference.The ABA content in LA134 new leaf,inverted trifoliate leaf and main stem were all higher than 79266 and 04D893.The ratio of Z/ABA,GA/ABA,IAA/ABA,?GA+IAA?/ABA in 79266 and 04D893 newly developed leaves was significantly higher than that of dwarf lines.Changes in endogenous hormone content and ratio of endogenous hormone content of parents and dwarf strains were closely related to plant height,among which GA content in newly developed leaves had the highest correlation with plant height.3.Response of plant height to gibberellin.The plant height of both 04D893 and dwarf strains increased with different concentrations of gibberellin,and the four materials were gibberellin sensitive.The high growth rate of 04D893 and the short strains varied with the varieties.04D893 was the most sensitive to gibberellin,and LA134 was the least sensitive to gibberellin.Under gibberellin treatment,the number and length of four material internodes increased correspondingly,and the internode elongation effect was mainly concentrated in the upper part.4.Phenotypic effects of plant height related molecular markers.By analyzing the main stem height and side branch length data of the screened F3 population,the materials labeled with different genotypes of HM171^ARS203 segments showed no significant difference in main stem height and side branch length.The results showed that there was a gene controlling the lateral branch length in the HM171^ARS203 segment,and the gene was closest to the marker HM171.The results were consistent with the previous QTL related to plant height.It was basically verified that the QTL related plant height identified in the early stage was the QTL related lateral branch length.