International Journal of Horticulture, 2016, Vol.6, No.24, 1-7
2
the type and magnitude of gene action, which will help in choice of the type of breeding method to be utilized for
the improvement of the yield and related traits.
1 Materials and Methods
The thirty hybrids obtained through hand pollination during
kharif
2014 at Main Pulses Research Station,
Sardarkrushinagar Dantiwada Agricultural University, Sardar Krushinagar using newly developed six cytoplasmic
male sterile lines and five diverse restorers as pollinators in a line x tester mating design. The experiment was
conducted during
kharif
2015. The latitude and longitude were 240 12' N and 720 12' E. The altitude and soil type
were 154.5 m and loamy sand, for these location. Six cytoplasmic male sterile lines, five pollen fertility restorer
line as male parents, thirty synthesized hybrids and standard check viz. GTH 1, GT 101 and VAISHALI were
evaluated using randomized block design with three replications. Each genotype was represented by a single row
plot of 4.0 m length. The inter and intra row distances were 60 and 20 cm, respectively. All the agronomical
practices and plant protection measures were followed for raising the good crop. Observations were recorded on
five randomly selected competitive plants of each genotype in each replication for various characters i.e. plant
height (PH) (cm), number of branches per plant (BP), number of pods per plant (PP), pod length (PL) (cm),
Number of seeds per pod (SP), 100-seed weight (g) (TW), seed yield per plant (g) (SY), biological yield per plant
(g) (BY). Days to flower (DF) on the basis of 50% plants of each genotype flowered, days to maturity (DM) on
the basis of 80% plants of each genotype matured were recorded. The protein content (PC) was estimated in
percentage by using Nuclear Magnetic Resonance Technique (Tiwari et al., 1974). Harvest Index calculated by
using following formula ((Economic yield/Biological yield) ×100). The replication wise mean values were used
in statistical analysis. The data were analyzed for combining ability (general and specific) following Kempthorne
(1957).
2 Results and Discussions
The analysis of variance for combining ability by partitioning the total genetic variance into general combining
ability representing additive genetic variance and specific combining ability as a measure of non-additive genetic
variance was carried out for different characters and are presented in Table 1. The mean sum of squares due to
lines were significant for all characters except number of branches per plant, number of pods per plant, number of
seeds per pod, pod length, 100-seed weight and protein content. The mean sum of squares due to tester were
significant for plant height, number of branches per plant, number of pods per plant, seed yield, harvest index,
biological yield and leaf area. The mean sum of squares due to line x testers interaction were significant for all the
characters except plant height, revealed the significant contribution of hybrids for specific combining ability
variance components. The mean squares due to tester were larger in magnitude for number of pods per plant,
number of seeds per pod than the lines indicated greater contribution of tester to these traits.
The ratio of σ
2
gca/σ
2
sca being more than unity was found for days to flowering, days to maturity, plant height and
biological yield, which suggested greater role of additive genetic variance in the inheritance of these traits. These
traits can be improved further as a source of favourable genes for earliness and yield through selection of desired
transgressive segregants from segregating generation. The above results were in accordance with the findings of
Sharma et al. (1972) and Sreelakshmi et al. (2011). For plant height additive gene action reported by Shrinivas et
al. (2000), Ajay kumar et al. (2001), Chauhan et al. (2003) and Patel (2004). For biological yield additive gene
effect reported by Basavarajaiah et al. (2000) and Bhadru (2008). For remaining traits non-additive type of gene
action was predominant. and its components have also been reported by Chaudhari et al. (1980), Venkateswarlu
and Singh (1982), Omanga (1984), Saxena et al. (1989), Sarode et al. (2009), Vaghela et al. (2009) and Pandey
Praveen et al. (2014). Preponderance of non-additive genetic variance suggested the relevance of heterosis
breeding in pigeonpea. Highly significant gca effects for seed yield among parents exhibited by CMS GT 603 A
and GTR 95 (Table 2). Which had also siginificant gca effects for its contributing traits
viz.
number of pods per
plant, number of branches per plant, number of seeds per pod, pod length, biological yield and leaf area. Parents,
CMS GT 33 A, CMS GT 288 A, GTR 52 and GTR 8 for earliness, CMS GT 33 A, GTR 8, CMS GT 301 A and
CMS GT 288 A for dwarfness, CMS GT 33 A, GTR 18 and CMS GT 301 for protein content found good general
combiners for respective traits. Among thirty hybrids three hybrids each for days to flowering, days to maturity,
