1. Department of Plant Breeding & Genetics, Bhubaneswar, Odisha, India-751003
2. Department of Soil Science and Agricultural Chemistry, Bhubaneswar, Odisha, India-751003
3. Department of Plant Physiology, OUAT. Bhubaneswar, Odisha, India-751003
Author
Correspondence author
Legume Genomics and Genetics, 2015, Vol. 6, No. 1 doi: 10.5376/lgg.2015.06.0001
Received: 29 Dec., 2014 Accepted: 30 Jan., 2015 Published: 25 Feb., 2015
Grain legumes occupy unique position in Indian agriculture. Besides forming a sustainable component of Indian agriculture, they are a major source of vegetable protein to the larger mass of the country that are basically vegetarian in their food habit. Black gram grain contains about 25% protein, 56% carbohydrate, 2% fat, 4% minerals and 0.4% vitamins. Black gram is said to have originated in India, where it is most widely grown and highly esteemed grain legume (Chatterjee and Bhattacharya, 1986). It is well known that 50 g. pulses/person/day should be consumed in addition to other sources of protein such as cereals, milk, meat and egg, which is a very difficult task to achieve as the production and productivity of pulse crop including black gram is very low. Diallel analysis, as proposed by Griffing (1956), measures the combining ability of parents to be used in hybridization and helps the crop breeder in choosing the desirable parents for hybridization program. Besides this, diallel analysis also guides the breeder in choosing appropriate breeding method by estimating the GCA (general combining ability) and SCA (specific combining ability) variances governing the traits and by determining the components of genetic variance viz. additive and dominance variances assuming epistasis being absent. The present study was undertaken to study the GCA and SCA effects and variances of some black gram parents and crosses, respectively for yield and other quantitative traits. Significant GCA and SCA effects provide information to determine the efficacy of breeding for improvements in given traits and they can be used to identify the lines to be served as parents in a breeding program for further improvement (Kearsey and Pooni, 1996). In addition, this technique enables the breeder to combine desirable genes that are found in two or more genotypes (Dabholkar, 1992). Genetic parameters like narrow sense heritability and degree of dominance for seed yield and other quantitative traits were also estimated in this study.
Results
The analysis of variance for combining ability for yield and its attributing characters are presented in Table 2. The analysis of variance revealed significant differences existed among the parents and crosses for all the traits under studied in advanced generation like F1. Due to segregating behaviour of the crosses the possible options of significant differences for genotypes arose for these traits under studied. The ANOVA revealed that mean squares due to genotypes were distinctly significant for all the yield attributing traits under evaluation indicating presence of sufficient amount of variability among the parents and among the crosses. The percentage of heritability in broad sense was highest with days to maturity (94.78%) followed by days to 50% flowering (94.67%). The heritability narrow sense was highest with number of number of seeds/pod (29.69%) followed by pod length (27.95%) (Table 4).
Table 1 Varieties/Landraces used in hybridization programme
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Table 2 Analysis of variance for different yield parameters of parents and F1 in blackgram
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Table 3 Analysis of variance for combining ability of different yield parameters of blackgram in F1 generation
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Table 4 Estimates of variance components and degree of dominance for yield, yield contributing characters in F1 generation
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Days to 50% flowering
In the present study the genotypes for lowest days to flowering was exhibited by PU-35 (33.46) followed by LBG-17 (34.69) whereas highest days to 50% flowering was recorded with B-3-8-8 (39.56) followed by Keonjhar Local (39.03) and PU-30 (37.70) (Table 5). Out of 8 parents 4 parents exhibited positive gca effect (3 were significant) for this character whereas rest 4 parents exhibited negative gca effect (3 were significant). PU-30 (-0.39) and PU-35 (-0.38) had the lowest general combining ability effect. Whereas positive and significant gca effect was exhibited by Keonjhar Local (0.35) followed byLBG-17 (0.30) for this character a low gca signifies early maturity (Table 6). For days to 50 % flowering hybrid TU-94-2 × Keonjhar Local was adjudged as earliest crosses among all with a mean of 32.36 days to flower 50% followed by PU-30 × Keonjhar Local (32.99). OBG-31 ×Keonjhar Local (38.14) was having the maximum period to flower 50% of the total masses (Table 7).The estimates of sca effects ranged from -2.76 to 2.32. The best specific combiners for early flowering were B-3-8-8×Keonjhar local (-2.76) followed by PU-30×Keonjhar Local (-2.71) and PU-30×OBG-31 (-2.30) (Table 8). This indicated that these crosses in combination with other parents could result in an early maturity. This is desirable since a negative sca signifies early maturity.
Table 5 Mean performance of parents for yield and yield attributing traits of blackgram in F1 generation
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Table 6 General combining ability effects of parents for different traits of blackgram in F1 generation
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Table 7 Mean performance of Hybrids for different traits of blackgram in F1 generation
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Table 8 Specific combining ability effects of hybrids for different traits of blackgram in F1 generation
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Days to maturity
Early maturing genotype was LBG-17 (68.41) followed by PU-35 (68.99) whereas Keonjhar Local was having the highest maturity period of 77.13 days followed by PU-30 (77.04) and B-3-8-8 (76.13) (Table 5). Out of 8 parents 5 parents exhibited positive gca effect (3 were significant) for this character whereas other 3 parents exhibited negative gca effect (2 were significant). TU-94-2 (-0.72) followed by OBG-31 (-0.59) had the lowest general combining ability effect for days to maturity.PU-30 would be the best general combiner for this character because we expect negative gca for the expression of days to maturity (Table 6). PU-35×Keonjhar Local took longest period to mature (75.64) followed by B-3-8-8 × OBG-31 (75.58) and OBG-17 × TU-94-2 (75.47). The earliest maturing cross was OBG-17 × OBG-31 (67.96) followed by TU-94-2 × Keonjhar Local (68.37). So the crosses with early maturing are desirable rather as compared to the late maturing one (Table 7). Among the 28 F1 hybrids highest positive sca was recorded with B-3-8-8 × OBG-31 (3.20) followed by OBG-17×TU-94-2 (3.00). For this character negative sca is desirable so significant negative sca effects were exhibited by PU-30×Keonjhar Local (-4.71) followed byOBG-17×OBG-31 (-4.64) and TU-94-2×Keonjhar Local (-4.09) (Table 8).
Plant Height
For plant height minimum plant height was recorded with TU-94-2 (21.00) followed by LBG-17 (21.83). B-3-8-8 (24.68) was having maximum plant height followed by PU-35 (24.37) and OBG-17 (23.72) (Table 5). Keonjhar Local (0.55) adjudged as the best combiner for this trait with significant positive gca effect followed by OBG-31 (0.45) whereas for plant height lowest calculated gca was viewed by TU-94-2 (-0.93) followed by OBG-17 (-0.44) (Table 6). The positive expression of gca for this character is desirable. The plant height is an important traitby which growth and vigour of plants are measured. In F1hybrids, B-3-8-8 × OBG-31 (26.63) was tallest among all the crosses followed byOBG-31 × Keonjhar Local (26.47) and LBG-17 × Keonjhar Local (26.23). Plant height is a major quantitative character which governed yield/plant (Table 7). The range of sca for plant height varied from -2.72 to 3.69. The cross OBG-17× PU-30 had the lowest sca value of -2.72 which indicated the cross combination resulted the plant type which was shortest among all followed by B-3-8-8 × PU-35 (-2.20) and OBG-17 × OBG-31 (-1.94) (Table 8).
Number of primary braches/plant
Keonjhar Local had maximum number of primary branches/plant (1.62) followed by TU-94-2 (1.56) and OBG-31 (1.50), lowest number of primary branches/plant was recorded with PU-30 (1.31) followed by LBG-17 (1.26) (Table 5). For this character the gca effect was ranging from -0.09 to 0.09. Keonjhar Local (0.09)exhibited significant positive general combining ability effects for number of primary branches/plant followed by OBG-31 (0.06). The lowest gca effect was recorded with the parent B-3-8-8 (-0.09) followed by PU-30 (-0.04) (Table 6). The F1 hybrid recorded with the highest number of primary branches/plant was PU-35 ×Keonjhar Local (1.67) followed byLBG-17× OBG-31 (1.67) and LBG-17 × Keonjhar Local (1.60). B-3-8-8 × TU-94-2 (1.18) had the lowest number of primary branches/plant among all the entries made (Table 7).The range of sca for number of primary braches/plant lies with -0.14 to 0.21 whereas B-3-8-8 × TU-94-2 (-0.14) had lowest sca effect followed byPU-30 × PU-35 (-0.12) whereas LBG-17×OBG-31 had highest sca effect (0.21) followed by PU-35 × Keonjhar Local (0.17) and TU-94-2 × PU-30 (0.16) for number of primary branches/plant (Table 8).
Number of clusters/plant
PU-30 exhibited lowest values for number of clusters/plant (5.36) followed by LBG-17 (5.44) whereas the maximum number of clusters/plant exhibited by Keonjhar Local (5.73) followed by OBG-31 (5.72) (Table 5). Among 8 parents 4 parents exhibited positive gca effect (3 were significant) for this character whereas rest 4 parents exhibited negative gca effect (2 were significant). OBG-17 (0.12) and TU-94-2 (0.12) exhibited significant positive general combining ability effects for number of clusters/plant. Whereas negative gca was recorded withPU-30 (-0.17), LBG-17 (-0.11) indicated this genotypes were not suitable for selection of this traits (Table 6). For number of clusters/plant the F1 hybrid TU-94-2× OBG-31 (6.14) had maximum ranking than all other hybrids followed by TU-94-2 × PU-30 (6.06) and PU-35 × Keonjhar Local (6.05). PU-30 × OBG-31 (4.48) had lowest number of clusters/plant (Table 7). The range of sca effect for this character varied from -0.85 to 0.62. The best specific combiner among the entire 28 F1 hybrid was PU-35 × Keonjhar Local (0.62) followed by TU-94-2 × PU-30 (0.61) and TU-94-2 × OBG-31 (0.53) whereas the lowest sca effect for this character was recorded with the cross PU-30× OBG-31 (-0.85) followed by PU-30 × Keonjhar Local (-0.67) (Table 8).
Number of pods/plant
Number of pods/plant was maximum with TU-94-2 (24.89) followed by PU-35 (24.77) and OBG-31 (24.73) and the lowest number of pods/plant was recorded with B-3-8-8 (22.29) followed by Keonjhar Local (23.85) (Table 5). A study of the gca effects of the parents for this character showed that OBG-31 (0.73) and Keonjhar Local (0.35) exhibited strong positive effect than other genotypes with respect to this character. Whereas the genotypes like B-3-8-8 (-0.81) and PU-30 (-0.27) were significantly differing from OBG-31 with regards to number of pods/plant (Table 6). The positive gca effect is desirable for selection parent for this character.OBG-31 × Keonjhar Local (26.99) had the highest pods/plant among all 28 F1 hybrids followed by OBG-17 × Keonjhar Local (26.77) and TU-94-2 × PU-30 (25.86). The lowest pods/plant was observed with hybrid OBG-17 × PU-35 (22.53) (Table 7). OBG-17 × Keonjhar Local (2.26) exhibited significant highest sca effect for this character followed by OBG-31 ×Keonjahr Local (1.70) and TU-94-2 × PU-30 (1.69). The sca for this character varied from -1.56 to 2.26. The significant lowest sca was recorded with OBG-17 × PU-35 (-1.56) followed by TU-94-2 × PU-35 (-1.21). Positive significant sca favours the selection this character (Table 8).
Number of seeds/pod
Maximum number of seeds/pod was resulted with OBG-31 (6.17) followed by PU-35 (6.00) and PU-30 (5.75) whereas lowest seeds/pod was recorded with LBG-17 (5.32) followed by TU-94-2 (5.45) (Table 5). Highest gca effect for this character exhibited by OBG-31 (0.33) followed by Keonjhar Local (0.13). The highest negative effect for this character was recorded with B-3-8-8 (-0.23) followed by LBG-17 (-0.13) (Table 6). Among 8 parents 3 parents exhibited positive gca effect (2 were significant) for this character whereas rest 5 parents exhibited negative gca effect (2 were significant).OBG-31 × Keonjhar Local (6.72) had maximum number of seeds/pod followed by PU-35 × Keonjhar Local (6.33) and LBG-17 × OBG-31 (6.18), OBG-17 × Keonjhar Local (6.18). The lowest number of seeds/pod was recorded with cross TU-94-2 × Keonjhar Local (5.23) followed by B-3-8-8 × LBG-17 (5.24) (Table 7). More the number of pods more is the yield/plant. The sca effect for this character ranged between -0.47 to 0.54. OBG-31 × Keonjhar Local (0.54), TU-94-2 × OBG-31 (0.54) followed by B-3-8-8 × PU-30 (0.49) whereas the lowest value of sca was associated with PU-30 × Keonjhar Local (-0.47) Followed by PU-30 × PU-35 (-0.46) (Table 8).
Pod length
The genotype OBG-17 (5.73) topped the list of pod length followed by OBG-31 (5.33) and LBG-17 (5.21), PU-30 (4.66) had lowest pod length followed by PU-35 (4.91) (Table 5). OBG-31 (0.20) registered significant highest gca effects for pod length followed by OBG-17 (0.09). PU-30 (-0.19) showed maximum significant negative effects for pod length followed by TU-94-2 (-0.09) (Table 6). For higher yield the parent with positive gca effect is desirable.LBG-17 × OBG-31 (5.77) topped the list followed by PU-35 × OBG-31 (5.66) and OBG-17 × PU-35 (5.54), B-3-8-8 × PU-30 (5.54) for this character in F1generation. OBG-17 × Keonjhar Local (4.66) had lowest pod length among all 28 crosses (Table 7). Specific combining ability effects revealed that the highest sca was observed with the hybrid B-3-8-8 × PU-30 (0.59) followed LBG-17 × Keonjhar Local (0.33) andPU-35 × Keonjhar Local (0.32). The lowest sca effect was observed with OBG-17 × Keonjhar Local (-0.50) followed by B-3-8-8 × PU-35 (-0.31). The sca effect for this character ranged from -0.23 to 0.24 (Table 8).
100 seed weight
Maximum 100 seed weight was recorded with PU-35 (4.92) followed by Keonjhar Local (4.91) and B-3-8-8 (4.90) whereas minimum 100 seed weight was associated with OBG-31 (4.17) followed by PU-30 (4.27 (Table 5). The general combining ability effects revealed that parent LBG-17 (0.08) had maximum significant positive gca effect for this character followed by Keonjhar Local (0.07), whereas maximum negative gca effect was observed for OBG-31 (-0.13) followed by PU-30 (-0.07) (Table 6). In F1 the cross combination of PU-30 ×Keonjhar Local (4.96) had the maximum value for 100 seed weight (4.78) which further followed by OBG-17 × LBG-17 (4.89) and LBG-17 × OBG-31 (4.76). The lowest 100 seed weight was recorded with PU-35 × Keonjhar Local (4.27) followed by PU-30 × LBG-17 (4.13) (Table 7). Specific combining ability effect for 100 seed weight ranged from -0.50 to 0.43. PU-30× Keonjhar Local had highest sca effect for 100 seed weight (0.50) followed by LBG-17 × OBG-31 (0.35) and OBG-17× LBG-17 (0.33). The lowest sca effect was observed in B-3-8-8 × OBG-31 (-0.43) followed PU-35 × Keonjhar Local (-0.42) (Table 8).
Yield/plant
Yield/plant is the most desirable character any of the breeding programme so in F1 generation Keonjhar Local (5.94) topped the list of high yielding parents followed by LBG-17 (5.74) and OBG-31 (5.73) (Table 5). The lowest yielding parents for F1 generation was TU-94-2 (4.98) followed by B-3-8-8 (5.03).For this character the gca effect ranged from -0.16 to 0.25. OBG-31 (0.25) had maximum significant positive gca effect followed by Keonjhar Local (0.24). OBG-17 (-0.16) and TU-94-2 (-0.16) witnessed the maximum negative gca effect for yield/plant followed by B-3-8-8 (-0.14) (Table 6). The mean yield per plant was recorded highest in PU-35 × LBG-17 (6.19) followed by OBG-31 × Keonjhar Local (6.16), LBG-17 × OBG-31 (6.15) andB-3-8-8 × PU-30 (6.14). The lowest recorded cross for yield per plant was PU-30 × PU-35 (4.59) (Table 7). For yield the range of sca varied from -0.64 to 1.02. Among the 28 F1 hybrids B-3-8-8 × PU-30 (1.02) had the highest sca effect followed by PU-35 × LBG-17 (0.71) and PU-30 × OBG-31 (0.48). The lowest sca effect was recorded with the cross PU-30 × PU-35 (-0.64) followed OBG-17 × LBG-17 (-0.63) (Table 8).
Discussion
The significance of GCA/SCA variance indicated that both kinds of gene effects are important in controlling the inheritance of all the studied traits (Table 3 and 4). The GCA and SCA ratio was less than one for all characters under studied proving presence of the non- additive genetic control. Similar results were reported by Seenaiah et al (1993), Shanti priya and Hariprasad Reddy (1999), Govindaraj and Subramanian (2001) and Manivannan (2002). It should be a concluding statement that dominant component were playing major role in expression of these characters. The components of both additive variance (D) and dominance variance (H) were worked out for all the studying traits indicating that the expression of all the traits is conditioned by both additive and dominance (non-additive) gene action. Similarly the relationship between additive(σ2A) and dominance variance (σ2D) and their ratio (σ2A/ σ2D) established the relation of non additive gene action. When the ratio is less than unity it secured the discussion for non additive generation means, non fixable part of gene action were still governing smoothly for these traits. Presence of non-additive gene action for these characters requires further maintenance of heterozygosity in the population. The ratio of σ2GCA /σ2SCA was approximately 1.00 which envisaged importance of both additive and non-additive components of variation in expression of these three important morpho-economic traits action was more affected by environment conditions than the additive type. From the above component heritability had been worked out.
The success of any breeding programme largely depends on the choice of the parent used in the hybridization. In addition to it, high mean was also considered as the main criterion for the selection of superior parents for breeding programme. Gilbert (1958) suggested that the parents with good per se performance would result in better hybrids. Further the parents having high gca effects could be useful since, the gca effect is due to additive gene action and is fixable (Sprague and Tatum, 1942).
The diallel analysis by Griffing’s method proved useful in the identification of parents for hybrid combinations, as the high correlation between the performance of the parents and estimates of the effects of their GCA and SCA seem to indicate. Significant mean squares for GCA and SCA confirm the presence of combining ability; however, SCA mean squares were larger than GCA. Combining ability can play a better role in identifying the precious genotypes for having specific cross combinations which can be used for heterosis and for further selection in segregating generations. Crosses like PU-35 × LBG-17, OBG-31 × Keonjhar Local, LBG-17 × OBG-31, PU-30 × Keonjhar Local,OBG-17 × LBG-17, PU-30 × OBG-31, LBG-17 × Keonjhar Local, B-3-8-8 × PU-30, OBG-17 × Keonjhar Local, TU-94-2 × PU-30, B-3-8-8×TU-94-2, PU-35× Keonjhar Local were promising in F1 generation (Table 7). This cross also possessed high mean seed yield with desirable yield components along with desirable plant stature. Hence this cross combination could favourably be considered for exploiting its vigour through heterosis breeding. However employing hybridization techniques in pulses including black gram is very tedious as the flowers are very small and delicate with cleistogamous nature. It is practically observed that through hand emasculation and pollination technique less than 5 per cent seed set is possible as proposed by Selvam and Elangaimannan (2010), Chakraborty et al. (2010) and Bhagirath et al. (2013). Hence, heterosis could be favourably exploited only if proper male sterility system is available. The presence of highly significant gca and non-significant sca may be due to additive and additive x additive interaction. Hence these crosses may be utilized for recombination breeding for further exploitation as these hybrids would throw segregants for higher yield.
Materials and Methods
The field experiment was undertaken at Experimental Block-II section of the department of Plant Breeding and Genetics, during pre rabi, 2013 to late rabi 2013-14. Geographically, the field experimentation site is located on 20o52’. N latitude,82o52’.E longitude and at an altitude of 25.9 m above the mean sea level and nearly 64 km west of the Bay of Bengal. It comes under the humid and sub-tropical climate zone of the state. In pre rabi (Sept-Dec.), 2013eight Black gram genotypes of different origin (7 improved variety + 1 promising local) were presented in Table 1. were utilized as parents to obtain 28 hybrid combinations according to a diallel crossing scheme (all combinations without reciprocals). Seeds of parental genotype were obtained by selfing. Hybrid F1 seeds were obtained by manual pollination. Further in laterabi (Dec-March) 2013-14 the parents and F1’s were grown at the EB-II of Plant Breeding & Genetics Department, OUAT, in three replicated randomized blocks. Plots consisted of two rows each of length 1 m. The distance between rows was 30 cm and between plants along the row was 10 cm. To avoid any border effect, plots were surrounded by a row of non-experimental material.The observations were recorded on ten quantitative traits viz. days to 50% flowering, days to maturity, plant height, number of primary branches/plant, number of cluster/plant, number of pods/plant, number of seeds/plant, pod length, 100 seed weight and yield/plant. Analysis of data for general and specific combining ability was carried out following Griffing’s (1956) Method II, Model I (fixed effect model). The statistical analysis was carried out using (AGRISTAT) software.
The combining ability analysis has been worked out according to the procedure suggested by Griffing’s (1956) Method II, Model I. The mathematical model for the combining ability analysis is assumed to be:
Yijkl = μ + gi + gj + sij + 1/bcΣi Σeijkl
(ij = 1, 2, 3 ….n;k = 1, 2, 3,………b;l = 1, 2, 3 ….c)
Where Yijkl, Mean of i × jth genotype in kth replication; μ, the population mean; gi, the GCA effect of ith parent; gj, the GCA effect of jth parent; sij, the specific combining ability (sca) effect for the cross between ith, jth parent such that sij = sji; Σi Σeijkl, the environmental effect associated with the ijklth individual observation on ith individual in the kth block with ith as female parent and jth as male parent. The usual restrictions such as Σgi = 0 and Σsij = sii = 0 (for each i) were imposed.
[Σ (Yi + Yii)2 – (4/n) Y2], Ss = Sum of squares due to sca,
Ss=Σ < Σ Y2ij – 1/ (n + 2) [Σ (Yi + Yii) 2 + 2/ (n + 1) (n + 2) Y2],
Me’ =Me1/r
Where Yi, Total of the array involving ith as a female parent; Yii, the value of the ith of the array; Y.., the grand total; Yij, the value of i x jth cross; MeI, the error M.S (Mean square) obtained from main ANOVA. The components of variances were estimated as suggested by Singh et al. (2003) in the following ways:
GCA expected M.S. =σ2e + (n + 2)/ (n – 2) σ2gi
SCA expected M.S. = σ2e + 2/(n – 1)2sij
Estimates of various effects
The various effects were estimated as follows:
GCA effect of ith parent = gi = 1/(n+2) [(Yi. + Yii) – 2/nY..]
SCA effect of ijth cross = Sij = Yij – 1/ (n + 2) [Yi. + Y.j + Yij) + 2Y/ (n + 1) (n +2)Y..]
Where gi and sij, The estimates of the GCA and SCA effects, respectively; n, Yi, Yii, Y.. and Yij, the same as explained earlier; Y.j, total of the arrays involving jth parent as a male; Yjj, the value of the jth parent in the array.
Estimation of combining ability effects
The general combining ability (GCA) effects and specific combining ability (SCA) effects were estimated as follows.
GCA effects = gi = [∑ (Xi + Xij) - X......]
SCA effects = Sij = Xij (Xi + Xij + Xj + Xij) + X......
Where,
Xi = total of jth column
Xij = value of jth parent
Authors’ Contributions
KKP carried out the overall experiment, AM and JP prepared the manuscript. BB and MK supervised the experiment as Chairman and member of the advisory committee for the doctoral degree thesis work.
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http://dx.doi.org/10.2134/agronj1942.00021962003400100008x