Diversity and Heterosis in Bittergourd (Momordica charantia) and Snakegourd (Trichosanthes anguina)

K.V. Peter and S. Rajan

College of Horticulture, Kerala Agricultural University, P.O.

Vellanikkara 680 654, India

Additional index words. germplasm, collection, evaluation, hybrid

Abstract. One hundred and twenty-eight accessions of bittergourd were collected, evaluated and morphologically described. F1 hybrids of 12 bittergourd accessions were produced and evaluated in two seasons. The bittergourd F1 hybrids Acc. 99 x Acc. 19, Acc. 20 x Acc. 14 and Acc. 14 x Acc. 9 expressed heterosis for earliness, fruit per vine and fruit yield. In snakegourd, 56 accessions were collected, evaluated and morphologically described. Fourteen snakegourd accessions were selected for making F1 hybrids that were evaluated in two seasons. The snakegourd F1s Acc. 15 x Acc. 58, Acc. 33 x Acc. 57 and Acc. 41 x Acc. 50 were heterotic for earliness and total fruit yield.

The authors acknowledge the Indian Council of Agricultural Research, New Delhi for sanctioning the Ad hoc research project which generated the information.

 

Bittergourd and snakegourd are popular tropical vegetables grown for their tender immature fruit. The reported role of momordicosoids in lowering blood sugar content in humans has upgraded bittergourd to that of a potentially very valuable medicinal plant. High fiber content in the fruit of snakegourd impart a high nutritive value to this cucurbit vegetable commonly grown in the warm humid tropics. India is a primary center of biodiversity in bittergourd and snakegourd. Our objectives were twofold. First, to survey, collect, evaluate, and document Indian germplasm of bittergourd and snakegourd. Second, to investigate F1 hybrid potential in bittergourd and snakegourd for earliness, uniformity in size, shape and color of fruit, and fruit yield. The monoecious nature of these crops makes them ideal for F1 hybrid seed production.

Materials and methods

Germplasm of bittergourd and snakegourd were collected from forests and farm plots in Kerala and Tamil Nadu, the southern states of India. Accessions were also made available by the National Bureau of Plant Genetic Resources, Vellanikkara, India for the present study. One hundred and twenty-eight accessions of bittergourd and fifty-six accessions of snakegourd were evaluated for days to first male flower anthesis, days to first female flower opening, days to first harvest, fruit per plant, fruit yield per plant, seeds per fruit, 100-seed weight, and total duration of the crop.

Based on fruit color and fruit yield per plant, 12 bittergourd accessions and 14 snakegourd accessions were selected for making F1 hybrids. Forty-three bittergourd F1 hybrids and seventy-five snakegourd F1 hybrids were evaluated in two seasons in order to assess heterosis in these two species.

Results and discussion

Bittergourd. Days to first male flower anthesis ranged from 34 days (Acc. 4) to 51 days (Acc. 27). Days to first harvest ranged from 52 days (Acc. 2) to 84 days (Acc. 123). Fruit per plant ranged from 9 (Acc. 18, Acc. 23 and Acc. 109) to 77 (Acc. 123). Fruit yield per plant ranged from 0.32 kg (Acc. 17) to 3.373 kg (Acc. 9). Fruit weight ranged from 25 g (Acc. 18) to 203 g (Acc. 22). Fruit length ranged from 9 cm (Acc. 123) to 42.1 cm (Acc. 36). There were green spiny, white nonspiny, white spiny, green nonspiny, greenish white spiny, and white highly spiny accessions. Seeds per fruit ranged from 10 (Acc. 29) to 46 (Acc. 20). Total crop duration ranged from 54 days (Acc. 18) to 124 days (Acc. 116). Twelve accessions (Acc. 81, 45, 99, 20, 21, 22, 14, 129, 9, 12, 2, and 10) were selected to develop 43 F1 hybrids that were evaluated for two seasons.

 

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Table 1. Salient features of three potential bittergourd F1 hybrids.

Days to Yield/ Fruit Fruit Total

Fruit first Fruit/ plant Fruit length girth Seeds/ duration

Hybrid color harvest plant (kg) wt (g) (cm) (cm) fruit of crop

Acc. 99 x Acc. 9 White spiny 63.0 57.0 5.0 88.0 22.0 14.0 12.0 130.0

Acc. 20 x Acc. 14 Green spiny 59.0 57.0 7.0 123.0 20.0 18.0 22.0 130.0

Acc. 14 x Acc. 9 Light green 63.0 37.0 6.0 100.0 22.0 15.0 30.0 130.0

Table 2. Salient features of three potential snakegourd F1 hybrids.

Days to Yield/ Fruit Fruit Total

Fruit first Fruit/ plant Fruit length girth Seeds/ duration

Hybrid color harvest plant (kg) wt (g) (cm) (cm) fruit of crop

Acc. 15 x Acc. 58 Green 49.0 15.33 4.33 288.33 62 15.67 32.67 136.0

Acc. 33 x Acc. 57 White 51.33 12.67 7.67 501.67 30.33 18.0 31.00 135.0

Acc. 41 x Acc. 50 White 55.0 24.0 9.0 401.67 52.33 16.67 35.00 135.0

Three promising F1 hybrids are Acc. 99 x Acc. 9, Acc. 20 x Acc. 44, and Acc. 14 x Acc. 9 (Table 1). The F1 hybrid Acc. 20 x Acc. 14 yielded 7 kg per plant and had a total crop duration of 130 days. The above F1 hybrids are now in large-scale cultivation.

Snakegourd. Days to first male flower opening ranged from 29 (Acc. 29 and Acc. 9) to 56 (Acc. 4). Days to first fruit harvest ranged from 51 (Acc. 29) to 88 (Acc. 15). Fruit per plant ranged from 5 (Acc. 6, Acc. 49) to 33 (Acc. 24). Fruit yield per plant ranged from 2.307 kg (Acc. 7) to 12.925 kg (Acc. 24).

Fruit weight ranged from 285 g (Acc. 16) to 1108 g (Acc. 25). Fruit length ranged from 34.9 cm (Acc. 21) to 113.5 cm (Acc. 22). Fruit girth ranged from 12.5 cm (Acc. 6) to 29.5 cm (Acc. 20). Fruit color combinations included white with pale green stripes, white, green striped, pale white, white with ash color stripes, green with white stripes, dark green with white stripes, green with white line, and green ashy. Seeds per fruit ranged from 4 (Acc. 2) to 88 (Acc. 48). Total crop duration ranged from 86 days (Acc. 28) to 129 days (Acc. 4). Fourteen accessions were selected to develop seventy-five F1 hybrids. Three of the most promising snakegourd F1 hybrids were evaluated for two seasons (Table 2). The F1 hybrid Acc. 41 x Acc. 50 yielded 9 kg of fruit per plant and had 24 fruit per plant.

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