Search

Common bean rust, Bean golden yellow mosaic virus (BGYMV), Bean common mosaic virus (BCMV), and Bean common mosaic necrosis virus (BCMNV) are devastating diseases of dry bean (Phaseolus vulgaris L.) in Central America and the Caribbean. The development of dry bean cultivars with enhanced levels of genetic resistance to these and other diseases is an important goal of the University of Puerto Rico (UPR) and other dry bean breeding programs in Central America and the Caribbean. PR1572‐19 (Reg. no. GP‐308, PI 692976) and PR1572‐26 (Reg. no. GP‐307, PI 692975) are multiple virus‐ and rust‐resistant pinto bean germplasm lines adapted to the humid tropics that were developed and released cooperatively in 2019 by the UPR Agricultural Experiment Station, the Instituto Dominicano de Investigaciones Agropecuarias y Forestales, and the USDA–ARS. Both PR1572‐19 and PR1572‐26 possess the bgm‐1 gene for resistance to BGYMV, the I and bc‐3 loci that provide broad resistance to all strains of BCMV and BCMNV in the United States and the Caribbean, and the Ur‐3 and Ur‐11 loci that confer comprehensive resistance to all known races of the bean rust pathogen. PR1572‐26 also has the SW12 quantitative trait locus marker associated with resistance to BGYMV. PR1572‐19 and PR1572‐26 produced mean seed yields similar to the check cultivar 'Santa Fe' in trials conducted in Puerto Rico and mean seed yields comparable to the pinto cultivar 'La Paz' in the Cooperative Dry Bean Nursery conducted in Puerto Rico. Both lines should serve as useful sources of resistance to BGYMV, BCMV, BCMNV, and bean rust for common beans of the Durango race that includes the pinto and great northern market classes. [ABSTRACT FROM AUTHOR]

Copyright of African Crop Science Journal is the property of African Crop Science Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Common bean (Phaseolus vulgaris L.) is extensively grown in production zones where water is limiting. Crop water use efficiency is the ratio of biomass or seed yield produced per unit of water evapotranspired in a particular environment. Transpi- ration efficiency (TE) is the ratio of yield per unit of water transpired. The objectives of this study were to: (i) determine the water use efficiency (WUE) for six common bean genotypes (BAT 477, Morales, SEN 3, SEN 21, SER 16, and SER 21) in the greenhouse and for two genotypes in the field (Morales and SER 16) and (ii) determine TE for two common bean genotypes using estimated evapotranspiration rates in the field. Three greenhouse trials and two field trials were conducted during 3 yr in Puerto Rico. Three water levels in the greenhouse and two in the field were applied. Actual evapotranspiration was estimated using the generalized Penman-Monteith model based on aerodynamic and surface resistance, and with drainage type lysim- eters in the field. Differences among genotypes for WUE were found in the greenhouse experiments, with SEN 3 and SER 21 showing superior WUE in several treatments. In the field, TE and WUE were affected by water level, and TE was consistent with previously reported coefficients for common bean. [ABSTRACT FROM AUTHOR]

Drought tolerance is an increasingly important trait in common bean ( Phaseolus vulgaris L.) due to the reduction in water resources, a shift in production areas and increasing input costs. The objective of this study was to evaluate 29 genotypes for drought tolerance under drought stress (DS) and reduced stress treatments in Juana Diaz, Puerto Rico. The use of DS and reduced stress treatments facilitated the identification of drought tolerant germplasm that also had good yield potential under more optimal conditions. Based on the results of seed yield under DS and reduced stress conditions, and DS indices, including the geometric mean (GM), stress tolerance index (STI) and percent yield reduction (YR), genotypes were identified with greater yield potential under the tested environment. Based on average GM over the 2 years, the superior common bean genotypes identified were SEA 5, G 21212, A 686, SEN 21 and SER 21. These genotypes performed well in both years and under both treatment conditions and thus may serve as parents for DS improvement and genetic analysis. [ABSTRACT FROM AUTHOR]

Abstract High ambient temperature (32/27 °C, day/night, 12 h photoperiod) applied prior to anthesis to Phaseolus vulgaris plants results in abnormal pollen and anther development during microsporogenesis. Scanning and transmission electron microscopy were used to examine anther and pollen morphology and pollen wall architecture after heat stress was applied to two genotypes that differ with respect to yield potential under high-temperature field conditions: one, a heat-sensitive, Mesoamerican genotype, A55, the second, a heat-tolerant, Andean genotype, G122. High-temperature treatment of both genotypes was applied 1–13 d before anthesis. Under heat stress, the heat-tolerant genotype showed anther and pollen characteristics that were generally similar to the low temperature controls. In contrast, after 9 d of heat treatment before anthesis, the anthers of the heat-sensitive genotype were indehiscent and contained abnormal pollen. Pollen wall architecture was also affected in the 12 and 13 d treatments. In addition to the morphological changes, the heat-sensitive genotype also experienced reduced pollen viability and reduced yield in high-temperature experiments conducted in both the greenhouse and field. [ABSTRACT FROM AUTHOR]