A Combining Ability Study in Muskmelon Using Line x Tester Analysis

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Cucurbit Genetics Cooperative Report 18:34-36 (article 15) 1995

M.S. Dhaliwal
Dept. of Vegetable Crops, L.S. & F., Punjab Agricultural University, Ludhiana-141 004 INDIA

Muskmelon, (Cucumis melo L.), is predominantly a cross-pollinated crop, and its ability to produce plenty of seeds per fruit facilitates heterosis breeding. Pollination mechanisms (viz. monoecy, gynoecy and male sterility have been exploited for heterosis breeding. On the other hand, vigour is not depressed by inbreeding (3) and most cultivars have been developed by selection and controlled inbreeding. The present investigation was undertaken to estimate combining ability effects using line x tester analysis excluding parents. This information will be useful to identify superior cross combinations that could be pursued for the development of superior cultivars and/or hybrids.

Material and methods: Thirty F1 hybrids involving two females (one monoecious and one gynoecious) and fifteen testers were grown during summer 1993 using three replications in RBD. Data were recorded for eight economic characters and were analysed following model of Kempthorne (1).

Results and Discussion: The ANOVA for the design (Table 1) revealed significant differences between hybrids for all the characters studied. Total variation among hybrids was further partitioned into different components corresponding to the combining ability of lines, testers and lines x testers interaction. Significance of MS due to lines (except node number to first female flower) and testers indicated that parents selected for the present study were genetically divergent. The results further indicated that both GCA and SCA effects were important for all the characters studied. These results confirmed earlier reports (2, 4). Further, var. SCA hybrids accounted for greater part of the variation compared to var. GCA (lines) and var. GCA (testers), indicating a preponderance of non-additive, non-fixible gene effects.

GCA estimates of selected parents are given in Table 2. Parents E142 and B112 are good general combiners for most of the characters studied. R271 was good general combiner for days to picking, yield per plot and TSS%., three important economic characters in muskmelon. C121 had a highest GCA estimate for days to picking. These parents could be used in single and multiple crosses for isolating probable transgressive segregants. Of two females, M221 was a good general combiner for TSS and W321 for days to picking, fruit weight, fruit number per vine, yield per plot and flesh thickness. Results pertaining to SCA estimates of selected F1 hybrids are listed in Table 3. Cross M221 x G161 exhibited significant and desirable SCA effects for all the characters studied. Cross W321 x H171 was second best. Cross W321 x M227 had significant desirable SCA estimates for yield per plot and TSS%., respectively. But these crosses are not expected to yield desirable recombinants as they do not involve good x good general combiners. These crosses need to be studied minutely for their commercial utilization.

Table 1. Analysis of variance for combining ability.

Source

d.f.

Days to first female flower

Node No. to first female flower

Days to picking

Fruit weight (g)

Fruit No. per vine

Yield/plot (kg)

Flesh thickness (cm)

T.S.S.
Replicates 2 4.13 0.236 15.34 2491.5 0.002 0.02 0.116 0.486
Hybrids 29 117.72** 0.895** 99.67** 118676.8** 0.324** 10.98** 0.560** 7.22**
Lines 1 642.67** 0.215 889.85** 829055.6** 0.711** 58.27** 2.304** 11.38**
Testers 14 111.86** 0.638** 88.52** 149543.2** 0.213** 10.71 0.547** 8.49**
Lines x Tester 14 86.58 1.200* 54.37** 37068.9** 0.408** 7.86** 0.449** 5.65
Error 58 4.37 0.136 6.30 3913.1 0.012 0.24 0.052 0.39
Var. gca Lines — 12.36 — 18.56 17599.7 0.007 1.120 0.041 0.127
Var. gca Testers — 4.13 -0.074 5.69 18745.7 -0.032 0.475 0.016 0.473
Var. sca hybrids — 27.40 0.355 16.02 11051.9 0.131 0.543 0.132 1.752

** = Significicant at P = 0.01

Table 2. General combining ability effects of selected parents.

Days to first female flower

Node No. to first female flower

Days to picking

Fruit weight (g)

Fruit No. per vine

Yield per plot (kg)

Flesh thickness (cm)

T.S.S. (%)
Females
M221 -2.267 -0.05 3.14** -95.9** -0.09** -0.80** -0.16** 0.36**
W321 2.267 0.05 -3.14** 95.9** 0.09 0.80** 0.16** -0.36**
Males
1 7 50 -0.73 0.0 -0.76 -178.34** 0.18** -2.37** -0.07 1.04**
E142 -5.32 -0.59** -3.09** 111.16** 0.50** 3.16** -0.06 0.96**
C121 4.27 0.09 -3.76** -98.3** 0.20** -1.32** 0.60** -1.38**
H173 7.35 0.21 4.58** -72.1** -0.04 -0.33 -0.09 1.62**
B112 -0.40 -0.32* -2.76** 83.8** 0.06 0.73** 0.36** 2.21**
R271 3.68 0.41** -3.59** -84.8** 0.23** 0.51** 0.08 0.71**
M223 2.12 0.23 7.58** 124..8 0.06 0.62** -0.49** 1.63**
M253 -1.40 0.11 -2.26** 37.8 -0.14** -0.32 -0.17 -0.38
E141 -7.65 -0.86* -2.42** 48.4 -0.22** 0.48* 0.00 -1.54**
C123 0.18 -0.09 5.58 377.6** -0.07 1.72** 0.55** -1.46

*, ** = Significant at P = 0.05 and P = 0.01. respectively.

Table 3. List of hybrids showing significantly desirable sca effects.

Days to first female flower

Node No. to first female flower

Days to picking

Fruit weight (g)

Fruit No. per vine

Yield per plot (kg)

Flesh thickness (cm)

T.S.S. (%)
M221 x 1 7 50 0.92 0.00 -3.31** 90.48** -0.09* 2.11** -0.01 0.39
M221 x E142 0.84 -0.52** 0.69 55.54** -0.21** -1.02** 0.16 1.14**
M221 x I181 -4.33** -0.42** -0.64 86.64** 0.39** 2.23** -0.17 0.39
M221 x B112 -5.58** -0.28 -0.64 -30.69** 0.16** 0.41* -0.07 -0.11
M221 x R271 -4.17** -0.85** 0.52 15.98** 0.06 0.14 0.14 1.23**
M221 x M223 -5.16** -0.20 -3.64** -139.7** 0.42** 1.16** -0.19* -0.94**
M221 x P253 -5.25** 0.05 -5.14** -1.02 -0.11* -1.57** -0.37** 0.14
M221 x G161 -3.41** -0.63** -2.81* 38.81** 0.12** 0.68** 0.33** 0.73**
M221 x E141 4.67 0.15 0.69 -162.7** 0.44** -0.35 0.06 0.31
M221 x C123 -0.50 -0.35* 3.02** -26.86** -0.11* -1.08** 00.32** 0.89**
W321 x E142 -0.84 0.52** -0.69 -55.64** 0.21** 1.02** -0.16 -0.14**
W321 x H171 -4.76** -0.48** -2.18* -44.97** 0.41** 1.20** -0.34** 2.19**
W321 x C121 -4.26** -0.40** 1.31 -93.81** 0.04 -0.26 -0.49** 1.02**
W321 x H173 -1.01 -0.72** -3.02** 84.02** 0.14** 1.05** 0.22* -0.47
W321 x M227 -1.84* -0.02 -1.02 -20.31** 0.31** 1.12** 0.36** 1.27**
W321 x M223 5.16** 0.20 3.64** 139.7** -0.42** -1.16** 0.19* 0.94**
W321 x P253 5.24** -0.05 5.14** 1.02 0.11* 0.57** 0.37** -0.14
W321 x E141 -4.67** -0.15 -0.69 162.7** -0.44** 0.35 -0.06 -0.31
W321 x K201 -2.76** 0.25 -6.36** 1.69 0.14** 0.54** -0.19* 0.19
W321 x C123 0.49 0.35* -3.02** 26.86** 0.11* 1.08** 0.32** -0.89**

*, ** = Significant at P = 0.05 and P = 0.01, respectively.

Literature Cited

  1. Kermpthorne, O. 1957. An Introduction to Genetic Statistics. John Wiley and Sons, Inc. pp. 468-473.
  2. Kitroongruang, N., W. Poo-Swang and S. Tokumasu, 1992. Evaluation of combining ability, heterosis and variance for plant growth and fruit quality characters in Thai-melon. Scientia Hort.. 50-79-87.
  3. Scott, G.W. 1933. Inbreeding studies with Cucumis melo.Proc, Amer. Soc. Hort, Sci. 29:485.
  4. Singh, M.J., K.S. Randhawa and Tarsem Lal. 1989. Genetic analysis for maturity andplant characters in muskmelon. Veg. Sci. 16:181=184.