After reading this article you will learn about:- 1. Origin of Bittergourd 2. Botany of Bittergourd 3. Breeding Objectives 4. Breeding Methods 5. Qualitative Genetics 6. Seed Production 7. Varieties.
Origin of Bittergourd:
According 10 Zeven and Zhukovsky (1975) the origin of bitter gourd remains unidentified. However, now it is considered of Indo-Malayan origin but has naturalized widely in the tropics and subtropics of the Old and New Worlds. It shares with M. balsamina, the balsam apple, the chromosome number In = 22. The species have similar karyotype and will hybridize with difficulty.
Bittergourd (Moniordica charantia L,2n = 2x = 22) is a rich source of iron and vitamin C and an important cucurbit grown both as rainy season and spring-summer season crop in India. It is also extensively grown in China, Japan, South East Asia, tropical Africa and South America. It is also known as hitter melon balsam pear Estimated area in India is 60,000 hectares.
Botany of Bittergourd:
Plants are monoecious annuals with medium size vines. Staminate flowers are small, yellow and borne on long slender pedicels. The pistillate flowers are solitary, have small pedicel and are easily distinguishable by oblong to long distinct green colour ovary.
Flowers are yellow. Leaves are segmented and have more length than width in the outline. There are five calyx and five corolla. Filaments are three, two are bilocular and one is unilocular. There are three short styles terminated by three bilobed or divided stigma. Anthesis and dehiscence occur early in the morning. Therefore selfing and crossing should be attempted in forenoon preferably in early hours.
The somatic chromosome number in bitter gourd is 2n = 2x = 22. The length of chromosome ranges from 1 to 2 µm. Six chromosome pairs are median (centromere in middle of chromosomes), three sub-median (centromere between mid-point and terminal end of chromosomes) and two sub-terminal (centromere near terminal end of chromosome) as reported by Varghese (1973).
Momordica dioica, also known as balsam apple, is a perennial dioecious climber with tuberous roots and small ovoid to ellipsoid spiny fruits. The species occurs throughout India and elsewhere in Asia, mostly in the wild state. It is grown for its non-bitter fruits.
The roots are medicinal and alkaloids have been reported in trace amounts. The chromosome number is 2n = 28. The karyotype is asymmetrical but without heteromorphic sex chromosomes as once reported. Sex dimorphism is apparently under genie control. Triploid and tetraploid cytotypes, presumably of autoploid origin, are known. Momordica dioica will not cross with M. charantia.
Momordica cochinchinensis (sweet gourd of Assam or kheksa) is cultivated in Asia for its immature fruits, which are cooked as a vegetable or used in curries. Oil used for cooking and illumination is extracted from the large black seeds.
For crossing purposes, female flower buds ready to flower in next 1-2 days are covered by cotton pad wrapping/small paper bags. Likewise male flower buds ready to open next morning are also covered. Pollination is carried out by rubbing staminate flower anthers from freshly opened flowers against the stigma of the protected pistillate flowers.
The crossed flowers are covered as above for few more days to avoid contamination/pollination from other plants brought by insects. Tagging is simultaneously done by writing the parentage and date of pollination. In order to increase crossed fruit set, other open-pollinated fruits already set may be removed to avoid inhibitory effects of these fruits on further fruit setting.
Kerala Agriculture University, Vellanikkara and Indian Institute of Horticultural Research, Bangalore, are rich sources of bitter gourd germplasm lines. In northern India, NDUAT, Faizabad, CSAUAT-Vegetable Research Station, Kalayanpur, GBPUA&T, Pantnagar and IARI, New Delhi and IIVR, Varanasi have collection of good number of promising lines of bitter gourd.
Breeding Objectives of Bittergourd:
1. Early fruiting
2. High female to male sex ratio
3. Fruit shape, size, colour and spininess as per consumers’ preference:
i. Short, oval, spiny, green, 7-8 cm long,
ii. Short, spindle, spiny, green, 15 cm long
iii. Medium long, spindle, spiny, green, 20 cm long
iv. Smooth, spindle, green, 20 cm long
v. Medium long, spiny, white, 20 cm long
vi. Long, spiny, white, 30 cm long
vii. Tough spines for long distance transportation
4. Immature seeds for longer period during green edible stage
5. High yield (a product of number of fruits and fruit weight)
6. Resistance to powdery mildew, downy mildew, mosaic
Breeding Methods of Bittergourd:
Inbreeding, pure-line selection in segregating generations and heterosis breeding as described in other cucurbits, particularly bottlegourds are applicable to bittergourd.
Qualitative Genetics of Bittergourd:
As per review of Nath et al. (1973), fruit colour (green vs white), seed colour (dark brown vs. whitish brown) and seed size (small vs. large) have been reported to be monogenically controlled with dominance of green over white colour fruit, dark brown over whitish brown seed and small seed size over large seed size, respectively.
Rare occurrence of complete gynoecism has been reported at IIVR, Varanasi by Dr. D. Ram and his associates in bitter gourd. Inheritance was examined in gynoecious line (Gy 263 B). The F2 and testcross data revealed that gynoecism in Gy 263B was found to be under the control of single recessive gene designated as gy-1.
Seed Production of Bittergourd:
Isolation distance for breeder/foundation and certified seed is 800 m and 400 m respectively. 1000 seed weight is 175 g and seed yield is about 6 q/ha. For hybrid seed production in India, 150 g female parent seed and 40 g male parent seed are planted in separate blocks within 1 unit of land (1000 m2).
The female and male flower buds are covered and U clipped with small paper bags in afternoon, prior to pollination next morning. Next morning open male flowers from male parent are collected and used in pollination of already covered female flowers which have opened by now.
Pollinated flowers are again covered and a thread is tied around pedicel to identify the crossed fruits. Open-pollinated fruits are removed as and when noticed.
Under insect proof net; covering of female and male flowers could be skipped. Pollination, can be performed daily in morning hours using open/male flowers as source of pollen grain on to the stigma of freshly opened female flowers. The crossed flowers need to be identified by tying a thread around pedicel. The seed multiplication ratio under normal situation is about 100.
Varieties of Bittergourd:
Pusa Do Mausami:
This variety has been obtained through selection from local germplasm at IARI and released by the same organization. It is suitable for spring-summer and rainy both the seasons. The fruits attain edible stage in about 55 days from sowing. The fruits are dark-green, long (18 cm), medium thick, somewhat club shaped having 7-8 continuous ridges. At edible stage, 8-10 fruits weigh one kg. VK-1 (Priya)
This variety came as a result of selection at Kerala Agricultural University, Vellanikkara in the local germplasm. It is characterized by extra-long fruits (40 cm) and heavy fruiting (about 50 fruits/plant). The fruits are white.
This was developed through selection from local materials of Rajasthan at IIHR, Bangalore and also released by the same institute as back as in 1973. The fruits are spindle shaped, attractive, glossy green with smooth regular ribs and thick flesh. The yield potential is about 120 q/ha in 120 days.
It is a dwarf-vine variety suitable for planting at higher plant density than that of long-vined other varieties. The fruits are glossy-green, medium long, thick and suitable as vegetable type, for stuffing and dehydration. It has been released by IARI release committee New Delhi. It is particularly suitable for spring summer season in northern plains. It takes about 55-60 days to first harvesting.
This has been developed at CSAUAT-Vegetable Research Station, Kalyanpur, Kanpur. It is a vigorous creeper. Fruits are long, thin and tapering. Yield potential is 100-125 q/ha in about 120 days. It is reported to be tolerant to fruitfly and mosaic. It is recommended for UP. Kalyanpur Sona
This variety has been developed at CSAUAT-Vegetable Research Station, Kalyanpur. The vine is creeper with green foliage. Fruits are medium long, thick and suitable for stuffing. The yield potential is 110-125 q/ha in 120 day crop duration. It is also reported to be tolerant to mosaic and fruitfly. It is suitable for UP. This has been duly notified by the Central Seed Committee in 1996 after its release by the UP state variety release committee.
Pant Karela 1:
This is a selection from inbreds of indigenous germplasm at Pantnagar released in 1999 by UP state variety release committee. Fruits are thick, 15 cm long. Yield is about 150 q/ha. Coimbatore Green It is a local type selected at TNAU, Coimbatore. Fruits are extra-long, upto 45 cm, dark green weighing 300-400 g. Yield potential is 180 q/ha.
Coimbatore Long White:
Fruits are extra-long (45 cm) and white.
Pusa Hybrid 1:
Medium long (14 cm), attractive green fruits.
It has been developed by pedigree method from a cross of Green Long x Delhi Local at MPKV, Rahuri. Fruits are dark green, 25-30 cm long and prickled. Yield potential is about 200 q/ha in 150-180 days.
Common hybrids of bitter-gourd by private seed companies in India are Chaman. Nikita. Abhishek. Green Butaka, Hita, Ishila. Prachi, Palec, etc. In South east Asia, the varieties/hybrids are long, cylindrical, smooth skinned, light green or whitish in colour.