Yield components, harvest index and leaf area efficiency of a sample of a wild population and a domesticated variant of the common bean Phaseolus vulgaris

Common bean (Phaseolus vulgaris L.) is the most important legume for direct human consumption worldwide. It is a rich and relatively inexpensive source of proteins and micronutrients, especially iron and zinc. Bean is a target for biofortification to develop new cultivars with high Fe/Zn levels that help to ameliorate malnutrition mainly in developing countries. A strong negative phenotypic correlation between Fe/Zn concentration and yield is usually reported, posing a significant challenge for breeders. The objective of this study was to investigate the genetic relationship between Fe/Zn. We used Quantitative Trait Loci (QTLs) mapping and Genome-Wide Association Studies (GWAS) analysis in three bi-parental populations that included biofortified parents, identifying genomic regions associated with yield and micromineral accumulation. Significant negative correlations were observed between agronomic traits (pod harvest index, PHI; pod number, PdN; seed number, SdN; 100 seed weight, 100SdW; and seed per pod, Sd/Pd) and micronutrient concentration traits (SdFe and SdZn), especially between pod harvest index (PHI) and SdFe and SdZn. PHI presented a higher correlation with SdN than PdN. Seventy-nine QTLs were identified for the three populations: 14 for SdFe, 12 for SdZn, 13 for PHI, 11 for SdN, 14 for PdN, 6 for 100SdW, and 9 for Sd/Pd. Twenty-three hotspot regions were identified in which several QTLs were co-located, of which 13 hotpots displayed QTL of opposite effect for yield components and Fe/Zn accumulation. In contrast, eight QTLs for SdFe and six QTLs for SdZn were observed that segregated independently of QTL of yield components. The selection of these QTLs will enable enhanced levels of Fe/Zn and will not affect the yield performance of new cultivars focused on biofortification.

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Improvement in photosynthesis, seed yield and protein content of common bean (Phaseolus vulgaris) by foliar application of 24-epibrassinolide under drought stress

Crop and Pasture Science ◽

10.1071/cp18424 ◽

2019 ◽

Vol 70 (6) ◽

pp. 535 ◽

Cited By ~ 1

Author(s):

Mahsa Mohammadi ◽

Majid Pouryousef ◽

Afshin Tavakoli ◽

Ehsan Mohseni Fard

Keyword(s):

Drought Stress ◽

Phaseolus Vulgaris ◽

Plant Growth ◽

Common Bean ◽

Protein Content ◽

Leaf Area ◽

Seed Yield ◽

Yield Components ◽

Intercellular Co2 Concentration ◽

Exogenous Application

Brassinosteroids (BRs), as a class of plant growth regulators, have been shown to affect different physiological traits of plants and counteract various stresses. We studied the possibility of increasing seed and protein yields of two genotypes of common bean (Phaseolus vulgaris L.) with the exogenous application of 24-epibrassinolide (EBL) in an experiment conducted during 2016 and 2017. Two levels of irrigation (optimal and drought stress) were applied to the main plots, and two genotypes of common bean (cv. Kusha and genotype COS16) and four concentrations of EBL (0, 2, 4 and 6 μm) were allocated to subplots in a factorial arrangement. At the flowering stage, drought stress was applied and bean plants were sprayed with EBL. The results indicate that drought stress reduced leaf area, yield components, seed yield and protein content. Moreover, substantial increase in intercellular CO2 concentration and decrease in transpiration rate, stomatal conductance and net photosynthetic rate were also recorded. However, exogenous application of EBL remarkably improved gas exchange attributes, leaf area, yield components, seed yield and protein content both under optimal irrigation and drought-stress conditions. Analysis of regression showed that, under both water-supply conditions, genotype COS16 would have highest seed yield when receiving 4.05 and 4.52 µm EBL, and cv. Kusha would have the highest seed yield by receiving 3.27 and 3.62 µm EBL. Therefore, EBL can be used as a plant growth regulator to enhance drought tolerance and minimise yield loss of common bean caused by water deficits.

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Genetic characterization at the species and symbiovar level of indigenous rhizobial isolates nodulating Phaseolus vulgaris in Greece

Scientific Reports ◽

10.1038/s41598-021-88051-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Evdoxia Efstathiadou ◽

Georgia Ntatsi ◽

Dimitrios Savvas ◽

Anastasia P. Tampakaki

Keyword(s):

Phaseolus Vulgaris ◽

Common Bean ◽

Phylogenetic Affiliation ◽

Rhizobial Inoculation ◽

Rhizobial Species ◽

The Common ◽

First Time ◽

Of Greece ◽

Rhizobial Isolates

AbstractPhaseolus vulgaris (L.), commonly known as bean or common bean, is considered a promiscuous legume host since it forms nodules with diverse rhizobial species and symbiovars. Most of the common bean nodulating rhizobia are mainly affiliated to the genus Rhizobium, though strains belonging to Ensifer, Pararhizobium, Mesorhizobium, Bradyrhizobium, and Burkholderia have also been reported. This is the first report on the characterization of bean-nodulating rhizobia at the species and symbiovar level in Greece. The goals of this research were to isolate and characterize rhizobia nodulating local common bean genotypes grown in five different edaphoclimatic regions of Greece with no rhizobial inoculation history. The genetic diversity of the rhizobial isolates was assessed by BOX-PCR and the phylogenetic affiliation was assessed by multilocus sequence analysis (MLSA) of housekeeping and symbiosis-related genes. A total of fifty fast-growing rhizobial strains were isolated and representative isolates with distinct BOX-PCR fingerpriniting patterns were subjected to phylogenetic analysis. The strains were closely related to R. anhuiense, R. azibense, R. hidalgonense, R. sophoriradicis, and to a putative new genospecies which is provisionally named as Rhizobium sp. I. Most strains belonged to symbiovar phaseoli carrying the α-, γ-a and γ-b alleles of nodC gene, while some of them belonged to symbiovar gallicum. To the best of our knowledge, it is the first time that strains assigned to R. sophoriradicis and harbored the γ-b allele were found in European soils. All strains were able to re-nodulate their original host, indicating that they are true microsymbionts of common bean.

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