Characteristics Of The Plant Architecture Mutant And Gene Mapping Of Short Petiole Gene In Soybean

Soybean is the important source of protein,oil and health promtors for human,also is the main feed for animals.According to the social progress and the living level,there is huge demand for soybean.Meanwhile,the area of cultivated land in China was gradually reduced with urbanization.In the past 20 years,Chinese soybean main imports from the United States,Brazil and Argentina,which makes Chinese soybean industry under many uncertain risks.The higher soybean yield in the limited arable land is only one resolution to meet the huge need.It became a choice to increase soybean self-sufficiency by greatly improving soybean yield.High-yield of soybean base on reasonable field group structure,while plant architecture can optimize the field group structure.Plant architecture refers to the s adaptive growth performance in specific circumstances,its essence is the result of the plant internal genes is regulated by the environmental factors.Revealing the molecular mechanism of plant architecture can provide the basis for plant molecular breeding.Our research team finds a plant architecture mutant M13H3-126（named pspa-1,photoperiod?sensitive plant architecture 1）mutated from Huaxia3（HX3）with ⁶⁰Co ray.This study aims at identifying the important agronomic characters,response on light temperature environment condition and exogenous hormone between wild type HX3 and plant architecture mutant pspa-1.Then we maked genetic analysis using F₂population deriving from the hybrid between HX3 and dwarf mutant pspa-1 with short petiole.The mutation gene was mapped the short petioles candidate genes on chromosome 1 in which 38.8 mb region among 4959886 bp to43833478 bp using Mut Map strategy,and the candidate genes and gene structure characteristics are analyzed in bioinformatics.The main results were as follows:1.The differences in main agronomic traits were compared between mutant and wild type in summer Guangzhou.The results showed that there was no significant difference in the average flowering time between mutant pspa-1（43±0.3 d）and wild type HX3（44±0.3 d）in yield.The plant height of HX3 was 98.28±7.78cm,which was significantly more than the pspa-1 plant height of 61.87±7.31cm.It was also found that the height of the first pod（11.67±2.17 cm）,seed weight per plant（156.22±45.27 seed）and the pod number per plant（27.35±8.93 g）of HX3 was the most significantly high than the height of the first pod （1.46±2.00 cm）,seed weight per plant（107.00±35.73 seed）and the pod number per plant（17.02±4.43 g）of pspa-1.It revealed that the node numbers（20.80±1.2 node）,effective pod numbers（101.70±28.10 pod）and the grain weight of 100 seeds（19.32±1.60 g）of HX3was significantly higher than the node numbers（17.90±0.77 node）,effective pod numbers（70.75±20.13 pod）and the grain weight of 100 seeds（17.02±4.43 g）of pspa--1.There are no significant differences in the branch number and immature pod number between two materials.2.The differences in the traits between the mutant and wild type in different seasons.The plant height of HX3 in four seasons were as fellow:57.3±3.45 cm,64.9±6.78 cm,39.7±7.03 cm,The plant height of pspa-1 were 16.5±2.97 cm,40.1±0.87 cm,28.5±7.62 cm.Obviously,the plant height of HX3 was higher than pspa-1.At cold and long day condition,there was no significant difference of the plant height between two kinds of material planted on December 5^thand March 5^th,but there was the most significant difference of the plant height between two kinds of material planted on December 5^that cold and long day condition,it exclude that the mutant strains was influence by temperature and light condition.The petioles of HX3 on the whole plant were significantly higher than that of pspa-1,which demonstrated that the short petioles character of mutant pspa-1 is stable genetic in any environmental condition,it also revealed that the plant height and the petiole length control by different genes.3.The differences in response to photoperiods and temperature between the mutant and wild type.Under the treatment of combining photoperiods in climate chambers and temperature and extending the photoperiods,HX3’s plant height and petiole length were greater than pspa-1 on any condition;When the temperature is consistent,the plant height of pspa-1 in long day was 34.3±4.03 cm,which was higher than that in short day（25.8±3.89 cm）.Pspa-1’s plant height was 7.00±1.21 cm in natural condiction,it was shorter than the plant height（10.57±2.72 cm）on the contrary condition,which showed that the plant height of the mutant probably is regulated by the photoperiods.HX3 showed shade response in climate chambers,while pspa-1 performed shade tolerance.4.The mutation gene of short petioles was mapped.Genetic analysis showed that the short petiole gene was a single gene recessive trait.The short petioles candidate genes mapped on chromosome 1（4959886～43833478 bp）through the BSA-Mut Map strategy,the area had13 point mutations.These mutations were genotyped through In Del and d CAPS markers.The genotyping result showed that the two locis Chr01-19577484 and Chr01-23769461 were closely related to the short petiole trait of pspa-1.The sequencing data analysis and the existing materials in laboratory finalized Chr01-23769461 locus mutation caused the short petiole trait of pspa-1.5.Bioinformatics analysis of candidate genes.This study annotated the candidate gene mutations inter genic region on the NCBI web site for BLAST,the result didn’t find a gene or noncoding RNA transcript near the mutations.Using the c DNA of these two kinds of materials as template,we amplified a product of the length of 172 bp included the mutation,it indicated that there was a transcript near Chr01-23769461,and one end of the product was located in Chr01-23769458 to Chr01-23769704.So we suspected candidate genes maybe a new gene or non-coding RNA.