Morphological classification of genetic diversity in cultivated okra, Abelmoschus esculentus (L) Moench using principal component analysis (PCA) and single linkage cluster analysis (SLCA)

Abstract

29 okra accessions sourced from different agro-ecological regions in Nigeria and grown during the rainy season of 2007 at Abeokuta (derived savannah) were evaluated for genetic diversity using principal component analysis (PCA) and single linkage cluster analysis (SLCA). The experiment was laid out in a randomized complete block design (RCBD) with five replications. The accessions were classified into six and five cluster groups by PCA and SLCA respectively. The mean contributions of plant height, days to flowering, branches per plant, fresh pod width, mature pod width, fresh pod length, pod weight per plant, pod per plant, seeds per pod, and seed weight per plant were relatively high in the principal axes confirming the major contributions of these traits to seed yield in okra. The first four principal axes accounted for over 60% of the total variation among the 18 characters describing the accessions. Accessions 29, 9 and 14, which appears to be the most diverse may be useful as source for variable characters in okra improvement among the accessions studied been the most distant.

Genetic diversity estimates in landraces of pumpkin (Cucurbita moschata) from North Eastern Himalayan region of India using agro-morphological and molecular traits

“…The output of the PCA analysis confirmed the individual contributions of different quantitative traits to the total variations observed as well as to the fruit yield in pumpkin landraces. This agrees with the report of Nwangburuka et al (2011) working with okra. The traits that contributed most positively to PC1 were vine length, leaves/plant, days to first female flower production, fruit weight/plant, fruit diameter, fruit skin toughness, fruit skin thickness, flesh thickness, TSS and fruit yield.…”

Phenotypic plasticity of okra for yield and associated traits

“…Notably, grain yield per plant, fruit length and number of fruits per plant exhibited a significant correlation (Figure 2). The results are in accordance with Bhardwaj et al (2019) who indicated that grain yield contributed most to PC1, and similarly, Ahiakpa et al (2017), Amoatey et al (2015) and Nwangburuka et al (2011) reported high contribution by fruit length, hundredseed weight, number of seeds per fruit and yield per plant, respectively. A biplot between PC1 and PC2 (Figure 1) showed the contribution of various traits, which are responsible for variation in okra accessions.…”

Assessment of genetic variability among accessions of okra (Abelmoschus esculentus L. Moench)

“…Ahiakpa et al (2013) identifi ed lack of adapted cultivars, narrow genetic base of germplasm collections as well as disease and pest incidence to be responsible for the relatively lower yields in the sub-region. Kumar et al (2010) and Alake et al (2012) advocated for the need to develop new and superior genotypes to replace existing older and low-yielding genotypes. Plant breeders select and develop superior genotypes from existing variability within the germplasm.…”

“…Omonhinmin and Osarawu (2005) reported high genetic variability within Abelmoschus spp. However, Kumar et al (2010) noted that much of the variability was yet to be explored due to the relatively lower breeding activities on okra. A detailed understanding of the magnitude and pattern of genetic variability is required for the improvement of any crop.…”

“…A detailed understanding of the magnitude and pattern of genetic variability is required for the improvement of any crop. Plant breeders have thus employed several multivariate techniques including Metroglyph and Principal Component Analyses (PCA) to profi le the variability within the germplasm of diff erent crops (Aremu, 2011;Nwangburuka et al, 2011;Osarawu et al, 2013). Anderson (1960) proposed Metroglyph analysis, a technique that reveals patterns of morphological variation in crop species by reducing the complex interrelationship among accessions into a pictorial scatter…”