Genetic Mapping for Agronomic Traits in IAPAR 81/LP97-28 Population of Common Bean (Phaseolus vulgaris L.) under Drought Conditions.

Júlio César Ferreira Elias,Mariana Vaz Bisneta,Vânia Moda-Cirino,Pedro Soares Vidigal Filho,Maria Celeste Gonçalves-Vidigal,Qijian Song,Giseli Valentini,Thiago Alexandre Santana Gilio

doi:10.3390/plants10081568

Abstract

One of the significant challenges of common bean breeding is developing cultivars with high yields under drought conditions. The present study attempted to map quantitative trait loci (QTLs) and identify molecular markers that are linked to drought tolerance in the common bean. We evaluated 160 recombinant inbred lines (RILs), derived from the cross between the carioca cultivars IAPAR 81 (drought tolerant) and LP97-28 (susceptible to drought). In 2014 and 2015, two experiments were conducted (DS—drought stress, and NS—no drought stress). In the DS experiment, water suppression was performed at the flowering stages R5 to R6. The results of our experiments showed that drought conditions play an essential role in reducing most of the traits that were evaluated. RILs under drought conditions reduced the grain yield by 62.03% and 24% in 2014 and 2015, respectively. We identified 15 quantitative trait loci distributed on the chromosomes Pv01, Pv02, Pv03, Pv07, Pv08, Pv09, Pv10, and Pv11, related to grain yield, seed yield per day, 100-seed weight, number of pods per plant, plant height, number of days for flowering, and number of days to maturity. The characteristics of seed yield per day, 100-seed weight, and number of days to maturity showed that QTLs colocalized on Pv07. Identifying QTLs that are linked to drought tolerance in the RIL population IAPAR 81 × LP97-28 is of particular importance for common bean breeding programs seeking to improve carioca beans that are cultivated in regions with drought conditions, such as Brazil.

Highlights

The common bean is an essential legume for the human diet, as it represents a vital source of nutrition and income for people, especially those from African and Latin American countries [1,2,3,4]
In the area where we performed the experiments, during 2014 and 2015, the precipitation was insufficient for the optimal development of common bean plants
The evaluation of the recombinant inbred lines (RILs) population from the IAPAR81 × LP97-28 cross, under two different conditions of water supplementation, no drought stress (NS) and drought stress (DS), showed a reduction in grain yield, yield per day, and the number of pods per plant when plants were submitted to an environment with a reduction in water supplementation

Summary

Introduction

The common bean is an essential legume for the human diet, as it represents a vital source of nutrition and income for people, especially those from African and Latin American countries [1,2,3,4]. The common bean is considered to be a subsistence crop in several regions globally, especially regions that are characterized by soil with low-quality, adequate fertilization, and susceptibility to biotic and abiotic stresses. Among these stresses, a lack of rain is the primary cause of the low productivity of the common bean, since the cultivation of the mentioned legume relies mainly on rainfall. The incidence of short-term drought periods in the main common bean-producing regions, such as Brazil, Mexico, the United States, and African countries, tends to increase due to climate change, which negatively impacts global production and food security [5,6,7]. Efforts are necessary to improve the crop tolerance to stress conditions, drought, to reduce poverty and malnutrition in developing countries in tropical regions [8]

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