Selection of Superior Genotypes of Lima Bean Landraces by Multivariate Approach

Abstract

The knowledge of genetic diversity in plant population is essential to the success of plant breeding programs. Thus, previous characterization of landraces is one of the first steps before the indication of genotypes to these plant breeding programs. This study aimed to characterize, through morphological traits, and estimate the genetic diversity in landraces of lima bean (Phaseolus lunatus L.). Genetic diversity was estimated by using multivariate methods that selected individual landraces to be indicated for farmers and consumers. According to morphological traits proposed by Biodiversity International, the genotypes UFPI-667 and UFPI- 682 showed higher dissimilarity and high potential to be used in crosses since they are genetically distant and complementary. The principal component analysis identified positive and significant phenotypic associations between variables: pod length, pod width, and grain production. According to the multivariate methods used, the landraces UFPI-666, UFPI-650, UFPI-651, UFPI-687, UFPI-658, UFPI-673, UFPI-667, and UFPI-674 are potential candidates for selection since they have relevant features for lima bean breeding, such as shorter cycles and higher grain production. This study showed that multivariate analysis can be used as an effective tool to find potential traits in lima bean and can assist the lima bean breeders in the selection of potential landraces. Accessions UFPI-667 and UFPI-682 can be indicated as genitors for breeding programs, as they are genetically distant and complementary in their characteristics.

Evaluation of Lima Bean Accessions at High Temperatures

“…These results were expected and are considered important for producers and consumers of Lima bean, because larger seeds are more appealing to the market (ASSUNÇÃO NETO et al, 2022;BRITO et al, 2020). Traits with higher correlation magnitudes can be considered in selection strategies (ASSUNÇÃO FILHO et al, 2022).…”

“…No significant correlation was observed between other phenological traits and plant architecture, this result is supported by Ribeiro et al (2018) andAssunção Filho et al (2022) who reported that this result can be explained by the fact the selection of phenological traits was not always associated with plant architecture and high grain yield.…”

Lima Bean Populations Assessments via Reml/Blup Methodology

“…As shown in Table 2, the highest values for genetic variances were for the traits pod thickness (PT), the number of locules per pod (NLP), and seed width (SW), indicating potential targets for the lima bean breeding program. The number of locules per pod is positively correlated with pod length and width, allowing an indirect selection for these traits (ASSUNÇÃO FILHO et al, 2022). However, the experimental variance values were higher than the genotypic variance for all traits, indicating a strong environmental influence in the experiment.…”

“…Plant height is important for adaptation to mechanical harvesting (TEIXEIRA et al, 2017). The number of pods per plant is an important trait in lima bean breeding because it positively correlates with grain yield (ASSUNÇÃO FILHO et al, 2022).…”

“…The selection gains estimated via BLUP (Tables 4, 5, and 6) revealed that, in general, significant gains were obtained in the evaluated generation. The number of days to maturity, plant height, number of pods per plant, pod thickness, and seed width had the highest genetic gains, indicating that these populations could be used as the basis for breeding programs aimed at larger seeds and greater grain yield, which is of interest to producers and consumers (ASSUNÇÃO FILHO et al, 2022). 1…”