Cultivar improvement and varietal scenario of minor/under exploited pulses
The term underexploited as commonly applied to refer to species whose potential has not been fully realized. But the implication of the underutilized differs with the context in which it is being used, such as Geographically; Where it is underutilized, Socially; By whom it is underutilized, Economically; to what degree it is underutilized. It is thus underutilized species are differs with the context with which they are being used. For example, with regard to the geographical distribution, often a species could be underutilized in some regions but not in others. The cowpea is, for instance, a staple crop for millions of people in sub Sahara Africa, but the same is considered as an underutilized crop in some Mediterranean countries where it is grown in some restricted areas (Padulosi et al., 1987). Similarly chickpea considered by many Italian scientists an underutilized species in their country but it is a main pulse crop in many of the Asian countries including India.
Pulses, being rich in protein, are important ingredients in the Indian vegetarian diet. They are often grown in marginal lands and constitute an important component in the dryland farming system. In spite of their importance, the efforts done into the research and development of pulse crops have been rather marginal whereas problems confronting pulses improvement are enormous. This is the reason that the pulses production in the country has not increased in the same dimension as in the case of cereals and millets.
Among the various pulses grown in the country, chickpea or gram stands first contributing 29.37 and 37.98 percent of the total area and production under pulses, respectively. This is followed by pigeonpea, black gram (urdbean) and green gram (mungbean). Horsegram, Lentil, Lathyrus and mothbean are the unique pulses which this country raises in large area, but their cultivation is restricted to one or two states only.
Pea (Pisum sativum)
An important phase in pea cultivation in India began in the early seventies when the powdery mildew disease became a widespread phenomenon and virtually the entire country was engulfed by this disease. Consequently, pea area was almost reduced to half. A critical situation developed as both the commercial varieties, Type 163 and Harbhajan were susceptible to powdery mildew. Therefore intensive genetic and breeding work diverted towards powdery mildew resistance. Six strains (T 10, P 185, P 38, 6583, 6587 and 6588) were identified powdery mildew resistant (PMR) at Chandra Shekar Azad University of Agriculture and Technology, Kanpur.
The first PMR variety; ‘Rachna’ was commercialized in the mid-1980s, seed production of PMS peas stopped in 1985, and for the last two decades only PMR varieties are being approved for cultivation. The other major directions in pea breeding in India during the last 10-15 years are development of dwarf, leafless and extra early varieties maturing in about 100 days after sowing. Four dwarf and powdery mildew-resistant varieties; Aparna, Apoorva, Uttara and KPMR 144-1 were identified for commercial cultivation. The dwarf varieties give better response to inputs and produce 50% more grain per hectare compare to their tall counterparts in the same maturity group.
Lentil (Lens culinaris)
India is the largest lentil growing country in the world. A great majority of the varieties that were commercialized from local selections prior to 1980 were small-seeded microsperma lentils. The yield potential, being negatively correlated with seed size, it was only small-seeded varieties were found promising in multilocation trials. As a result, a large number of small-seeded varieties, such as L 9-12, K 75, Lens 830, Pant L 639 and Pant L 234 were recommended from All-India Co-ordinated Pulse Improvement project. However these varieties had no impact in the major lentil-growing tract of central India. As the farmers here does not accept small-seeded lentils. A paradox was thus created. The improved bold-seeded selections could not be released due to relatively lower yields and the more productive small-seeded varieties did not accepted by the farmers. A change in this situation was caused by the release of 2 varieties with bold seed in 1984: Shivalika (1000-grain weight 32g) and Malika (1000-grain weight 28g). The former was a product of hybridization (Pant L 2134 x Pant L 639), and the latter was a selection from Bundelkhand.
The most significant achievements were the development of rust resistant varieties; Pant L 406 and Pant L 639, bold-seeded varieties Shivalik and Malika, and early varieties Lens 830 and PKVL 1. The lentil breeding programme has concentrated on developing early varieties with reasonable yields. The macrosperma x microsperma hybridization was started in a big way, which was subsequently adopted at other centers and served as the main source of widening the genetic base and infusing genes into Indian lentils from geographically distant genotypes. Important turning point in lentil research in India came when a germplasm strain from Argintina, Precoz was received at IARI, New Delhi in 1982. A typical macrosperma lentil with about 44 g 1000 grain weight, almost colourless testa and yellow cotyledons, flowers within about 70 days. After purification and single plant selection, it was evaluated in different centers and found rust resistant. This single genotype has been used most widely in all lentil breeding program in the country as a donor of bold seed, yellow cotyledons, earliness, erect growth habit and rust resistance. Some of the early lentils that have promise in field trial are Lens 4603, 4625, 4626, 4630, 4659 and 4660.
Grasspea / Khesari (Lathyrus sativus)
Grasspea, popularly known as Khesari in India, has unique properties of drought and flood tolerance. The major research interest was to develop varieties with near-zero content of neurotoxin β-oxalyl amino alanine (BOAA)/ODAP in its foliage and grain which has been implicated to cause human lathyrism. The beginning was made with germplasm screening for BOAA content and other economic and agronomic traits, including yield. Mutation induction and hybridization were used to increase genetic diversity. The first low-BOAA (0.2%) variety, Pusa 24, was developed for commercial cultivation in 1974. It was followed by three more similar varieties of the LSD series i.e., LSD 1, LSD 3 and LSD 6 with low neurotoxin content ranging from 0.15% to 0.20% in seeds. The most significant achievement of Lathyrus research in recent years was isolation and development of the variety Bio L 212 (Ratan) in 1997 through exploitation of somaclonal variation, which has the lowest BOAA content (less than 0.02%) recorded so far in any cultivar.
Mothbean (Vigna aconitifolia)
Moth bean also known as Matki, Math, Dew bean (Vigna aconitifolia) has been known for high degree of adaptation in rainfed arid situation due to tolerance to drought and high temperature. However, with these adaptive virtues, the crop was characterized for primitive plant type, grain yield (300-400 kg/ha.), long maturity (90-95 days) these include old popular varieties T1, Baleswar 12, and Jadia. It was therefore, used basically for fodder purposes and conserving soil and soil moisture. In view of achieving the same alternation in plant type and curtailment in maturity have been achieved up to desired level. In this direction Central Arid Zone Research Institute has made significant contribution and released improved varieties through mutation breeding.
Present day varieties have different maturity growth with semi spreading, semi-erect and erect-upright plant type. These varieties suit to 450-500, 300-450, 150-300 and 130-150 mm rainfall, respectively with reasonable grain yield potential from 500-1400kg/ha have been developed.
CAZRI Moth 3
CAZRI Moth 2
Horsegram (Macrotyloma uniflorum (Lam.) Zverdc.):
Horsegram (Macrotyloma uniflorum (Lam.) Zverdc.) is a tropical arid legume crop grown traditionally in most parts of India due its greater adaptability to poor soils and adverse climatic conditions which are unsuitable to many other crops. The area under horsegram in India is 1.7 million hectare with a production of 0.74 million tonnes and prodcutivity of 494 kg/ha. (Kumar 2007). Major horsegram growing states are Karnataka, Maharastra, Orissa, Andra Pradesh, Tamil Nadu and Kerala.
As the varietal improvement in this crop, which had low variability, was negligent, mutation breeding was attempted to create variability and breed superior varieties. The breeding objective was to evolve an early, high yielding genotype to tolerant to yellow mosaic virus and powdery mildew and showing adaptability along with non-shattering pods.
Varieties suitable for Karnataka state
Hebbal Hurali 1
Selection from PLKU 32
Hebbal Hurali 2
Selection from EC 1
A selection from Bailhongal local
Photoinsensitive tolerant to YMV
Selection from Palampur local
High yielding 9-10 q/ha
Synchronised brisk podding behavior 7.5-11.5 q/ha.
Lablab bean (Lablab purpureus L.):
The avare (Lablab purpureus L.), (Synonym; field bean, lablab, Dolichos bean Hyacinth bean) is a neglected pulse crop, normally cultivated in dry regions of tropical and sub-tropical countries. It is a legume well suited to most tropical environments, as it is adaptable to a wide range of rainfall, temperature and altitude. There are mainly two broad groups; the bushy field varieties and the twining-pole garden varieties.
Since the crop was photo-sensitive, its cultivation was restricted to a certain season in the year. With the objective of developing photo-insensitive and dual purpose genotypes, many varieties have been developed by Tamil Nadu Agriculture University Combature and GKVK, UAS, Bangalore suitable for different agroclimatic conditions and which can be grown any season of the year.
Avare varieties developed by GKVK Bangalore
(Local Avare x Red typicus)
(Hebbal Avare-1 x US. 67-31)
(HA 3 x Magadi local)
10-12 q/ha dry seeds
45-50 q/ha of green pods.