Genetic Analysis and Gene Mapping for a Short-Petiole Mutant in Soybean (Glycine max (L.) Merr.)

Liu Liu,Zhao Zhao,Wang Wang,Gai Gai,Kong Kong,Bhat Bhat,Li Li

doi:10.3390/agronomy9110709

Abstract

Short petiole is a valuable trait for the improvement of plant canopy of ideotypes with high yield. Here, we identified a soybean mutant line derived short petiole (dsp) with extremely short petiole in the field, which is obviously different from most short-petiole lines identified previously. Genetic analysis on 941 F2 individuals and subsequent segregation analysis of 184 F2:3 and 172 F3:4 families revealed that the dsp mutant was controlled by two recessive genes, named as dsp1 and dsp2. Map-based cloning showed that these two recessive genes were located on two nonhomologous regions of chromosome 07 and chromosome 11, of which the dsp1 locus was mapped at a physical interval of 550.5-Kb on chromosome 07 near to centromere with flanking markers as BARCSOYSSR_07_0787 and BARCSOYSSR_07_0808; whereas, the dsp2 locus was mapped to a 263.3-Kb region on chromosome 11 with BARCSOYSSR_11_0037 and BARCSOYSSR_11_0043 as flanking markers. A total of 36 and 33 gene models were located within the physical genomic interval of dsp1 and dsp2 loci, respectively. In conclusion, the present study identified markers linked with genomic regions responsible for short-petiole phenotype of soybean, which can be effectively used to develop ideal soybean cultivars through marker-assisted breeding.

Highlights

Plant canopy architecture is an important agronomic trait for improving the yield potential in soybean and other legumes crops [1,2]
Considering the ideal soybean architecture model proposed as compact plants with a small stature as well one or two branches [1], dsp mutant provides a valuable genetic resource for the development of a soybean ideal plant-type
Number below every simple sequence repeats (SSR) marker means recombinant individual number. These results demonstrated that the short-petiole trait of dsp mutant is controlled by two recessive genes even though the segregation ratio in F2 population of HDS-1 × dsp was significantly different from a 15:1 ratio (χ2 = 11.16, p = 0.00) in the 2014 field experiment

Summary

Introduction

Plant canopy architecture is an important agronomic trait for improving the yield potential in soybean and other legumes crops [1,2]. Ideal canopy structure with suitable leaf area index values has advantages of increasing light interception efficiency, that leads to increased photosynthesis as well as accumulation of photosynthetic assimilates, and eventually results in a higher yield [3,4]. It has been suggested that the desirable leaf area index of a population can be achieved by developing new cultivars for dense planting [1]. The interception capacity of crops on both direct and diffuse solar radiation is expected to increase under a horizontal canopy of dense seeding [5]. Kokubun (1988) investigated the characteristics of high-yielding soybean cultivars and proposed a high-yield ideotype model with the upper leaves vertically closed. The fraction of light absorption by the lower surface will be increased in Agronomy 2019, 9, 709; doi:10.3390/agronomy9110709 www.mdpi.com/journal/agronomy

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