Multivariate and Association Studies in Short Duration Pigeonpea [Cajanus cajan (L.) Millsp.] Genotypes

Abstract

Background: Absolute understanding of the relationship between yield and yield attributing traits contributing to variance is predominant in a breeding programme. To study the multivariate analysis and interrelationship among the yield and yield attributing traits in the pigeonpea, 68 genotypes were subjected to principal component analysis and association studies. Methods: The 68 pigeonpea genotypes were raised during two seasons viz., rabi, 2019-2020 and rabi, 2020-2021 in a randomized complete block design with two replications. The two-season data was pooled and utilized for multivariate and association studies. Result: The total variance was split into 12 principal components. Four principal components were found to have eigen values more than one and explained 78.75 per cent of the total variance. The correlation studies revealed that, the single plant yield was highly correlated with the traits viz., days to 50 per cent flowering (rg=0.213, P less than 0.05), days to maturity (rg=0.347, P less than 0.01), plant height (rg=0.536,P less than 0.01), number of branches per plant (rg=0.331,P less than 0.01), number of clusters per plant (rg=0.705,P less than 0.01), number of pods per plant (rg=0.805,P less than 0.01), pod length (rg=0.481, P less than 0.01), number of seeds per pod (rg=0.231, P less than 0.05) and hundred seed weight (rg=0.505, P less than 0.01). Selection for these traits will improve single plant yield. Path analysis showed that the traits viz., number of pods per plant (0.871), shelling percentage (0.391) and hundred seed weight (0.744) had high positive direct effect on single plant yield, whereas the high indirect effect on single plant yield possessed by number of pods per plant through traits viz., days to maturity (0.316), plant height (0.421), pod bearing length (0.454) and number of clusters per plant (0.706).

Assessment of Genetic Diversity using D2 Statistics among the Medium Maturity Pigeonpea [Cajanus cajan (L.) Millspaugh] Genotypes

“…The minimum diversity was contributed by pods/plant (2.38%) followed by primary branches/plant (4.76%), days to 50% flowering (6.19%) and plant height (8.10%). This is in conformity with Naing et al [12] when they reported that more contribution towards genetic diversity for pigeon pea are days to maturity, pods/plant, days to 50% flowering and seed yield; Ranjani et al [8] observed that maximum contribution towards the genetic diversity for the traits i.e., 100-seed weight and days to maturity; Sandeep et al [14] reported maximum contribution for seed yield, 100-seed weight and days to 50% flowering [15].…”

“…These all genotypes were grouped into six clusters by using Toucher's method based on eight quantitatively inherited characters which represent the vast genetic diversity and it could be used for further crop improvement programmes. Similar results were also reported by previous researcher i.e., Ranjani et al [8] and Sharma et al [9] observed seven and nine cluster groups from 68 genotypes, respectively; Kandarkar et al [10] showed that the twentyseven genotypes were grouped into six clusters. The present investigated results revealed that among the six clusters highest number of genotypes were included in cluster I (16) whereas all the other five clusters comprised of one genotype per cluster (Table 2).…”

Assessment of genetic diversity and path coefficient analysis for grain yield in pigeon pea (Cajanus cajan L. Millsp.)

“…The difference in magnitude between Genetic Coefficient of Variation (GCV) and Phenotypic Coefficient of Variation (PCV) was minimal for all traits, indicating a reduced influence of environmental factors on trait expression. Several studies, including those conducted by Ranjani et al (2021) [8] , have reported minimal variation between GCV and PCV for various characteristics in pigeonpea. According to Burton (1952), this suggests that the observed variability in the traits is predominantly due to genetic factors rather than environmental influences.…”