Introduction
In the protein-rich group of crops, red gram or pigeonpea [Cajanus cajan (L.) Millsp.] occupies an important place among rainfed resource poor farmers because it provides quality food, fuel wood, and fodder. Its soil rejuvenation qualities such as release of soil-bound phosphorous, fixation of atmospheric nitrogen, recycling of soil nutrients, and addition of organic matter and other nutrients make pigeonpea an ideal crop of sustainable agriculture in the tropical and sub-tropical regions of India. India is the major pigeonpea growing country and it accounts for 36.3 lakh hectare area and 27.6 lakh tonnes annual production with productivity of 760kg per hectare (Anon., 2012).
Why we need hybrids in pigeonpea?
The pigeonpea area, production and productivity trends in India in last five decades showed that there was about 2% increase in the area per year but the yield levels were stagnated around 600-700 kg per hectare. The best remedy is to increase productivity by breaking yield plateau through development of hybrids.
Advent of Hybrid Pigeonpea Technology
The concept of developing commercial hybrids in pigeonpea was developed at ICRISAT in 1974, when a source of genetic male-sterility (GMS) was identified.
Production constraints
The removal of 50 % of the fertile plants from seed production plot at the stage of flowering is time consuming and costly. Inadequate knowledge of the seed growers regarding multiple the multiple seed production (Dalvi et al., 2010)
To overcome the production constraints
To overcome the production constraints the efficient cytoplasmic - nuclear male-sterility (CMS) system was planned. The development of two good CMS sources one at ICRISAT (Saxenaet al., 2005) and another at Gujarat Agriculture University (Tikka et al., 1997). The former CMS was derived from C.cajanifoliusand designated as A4 system; while the later source was derived from C. scarabaoidesand designated as A2 system.
GMS-based Pigeonpea Hybrids - The Starter Technology
The existence of considerable magnitude of heterosis for seed yield (Solomon et al., 1957). An elaborate search for a male-sterility system was made in the germplasm and a breakthrough was achieved by Reddy et al. (1978), who reported plants with translucent anthers, which turned out to be a stable (ms1) GMS source. Five years later, Saxenaet al. (1983) reported another nonallelic (ms2) source of GMS that was characterized by brown anthers. As a result, first GMS based hybrid ICPH 8 was released (Saxena et al., 1992).
Development of CMS Systems - a Breakthrough
The development of CMS became imperative. The strategy was to induce CMS by placing pigeonpea genome in wild cytoplasm through hybridization. Out of seven systems of sterile cytoplasmsA2 and A4 systems are effective because of their stability under various agro-climatic zones and availability of good maintainers and fertility restorers.
Seed Production of Hybrids and their Parents
-
Saxenaetal. (2013) found that maximum yield ranging from 1333 to 3040 kg/ha in some districts of Madhya Pradesh, Madhya Pradesh will be a good site for hybrid seed production.
Seed yield performance of hybrid
-
Saxenaetal. (2006) revealed that the on an average ICPH 2433(2996 kg/ha) and ICPH 2431 (2838 kg/ha) were the best and superior over control cultivar UPAS 120 (c) (2245 kg/ha) by a margin of 33 % and 26 % respectively.
-
Saxenaetal. (2005) observed that ICPH 2470, matured in 125 days and produced 3205 kg/ha seed yield.5 % yield advantage over the check. These hybrids also have acceptable seed size and produced the highest number of pods. From this trial, three hybrids ICPH 2470, ICPH 2438 and ICPH 2429 have been selected for further testing.
-
Saxenaand Nadarajan (2010) reported that the data indicated that all the hybrids had high levels of resistance to wilt and sterility mosaic diseases. The best hybrid was ICPH 3371 with 3013 kg/ ha yield (62% gain) and no disease incidence.
CMS Based world’s first hybrid GTH 1
The first CGMS based pigeonpea hybrid, GTH 1 was developed at SDAU, SK Nagar, by utilizing the cytoplasm of the wild species of Cajanusscarabaoides. Released by ICAR in 2004 for cultivation in Gujarat state and central zones of India.
-
Saxenaand Nadarajan (2010) found that GTH 1 (1830 kg/ ha) gave 54.70% yield superiority over the bestGMS hybrid AKPH 4101 (1183 kg/ ha) and 32% yield superiority over the best local variety, GT 101 (1330 kg/ ha).
-
Saxenaand Nadarajan (2010) conducted the 923 farm trials of ICPH 2671 over three years. The plot size for these trials varied for 0.2 to 0.4 hectares. The superiority of hybrid over the years varied from 23 to 37 %.
-
Saxenaand Nadarajan (2010) observed that on farm trials were conducted under both pure as well as intercrop situations and pigeonpea-soybean gave the highest yield advantage (93%) over pure line control variety.
Advantages of Hybrids:
Following advantages of hybrid Pigeonpea over cultivated varieties;
1) Increase grain yield
2) Enhance seedling vigour
3) Reduced seed rates
4) Greater drought tolerance
5) Greater disease resistance
Conclusion:
The hybrids represent a breakthrough in enhancing productivity in pigeonpea by focusing heterosis and thus improving yield per se. Despite the success of releasing high yielding GMS based hybrid, they are not adopted effectively due to the high cost of seed production. The development of the CMS system in pigeon pea was a great achievement and has provided a platform for enhancing the pace of research and development of hybrid pigeon pea. The presence of high level of realized heterosis in farmer’s fields has opened the way for commercialization of hybrid pigeonpea technology.
Dr.Mahesh Salunke
Department of Research & Development
J K Agri Genetics Ltd.
Hyderabad 500 016
References:
Dalvi, A. V.Saxena, K. B., Luo, R.H. and Li, Y. R. (2010).Euphytica,173:397-407
Anonymous (2012).http://faostat.fao.org/
Reddy, B.V.S., Green, J.M. and S.S. Bisen.(1978). Crop Sci.18:362-364.
Saxena, K.B, Kumar, R.V., Srivastava, N., and Shiying, B.(2005).Euphytica, 145: 291-296.
Saxena, K.B. and Nadarajan.N.(2010). Electronic Journal of Plant Breeding, 1:1107-1117.
Saxena, K.B., Chauhan, Y.S., Johansen, C., and Singh, L.(1992). Proc. Workshop on 'New Frontiers in
Pulses Research and Development’.Nov.10-12, 1989, Kanpur, India.58-69.
Saxena, K.B., Kumar, R.V., MadhaviLatha, K., and Dalvi V.A. (2006).Indian J. Pulses Res., 19:7- 16.
Saxena, K.B., Kumar, R.V.,Tikle, A. N.,Saxena, M.K.,Singh, V. G., Rao, S.K., Khare , D.K., Chauhan, Y.
S., Saxena, R.K.,Reddy, B.V.S.,Sharma, D., Reddy, L.J., Green, J.M., Faris, D. G.,Mula, M., Sultana,
R., Shrivastava, R. K., Gowada, C.L.L., Sawargaonkar, S.L. and Varshney, R.K.(2013).Plant Breeding,
Blackwell Verlag GmbH.
Saxena, K.B., Wallis, E.S., and Byth, D.E. (1983).Heredity.,51:419-421.
Solomon, S., G.P.,Argikar, M.S. Salanki, and Morbad, I.R. (1957).Indian J. Genet., 17: 90-95.
Tikka, S.B.S., Parmar, L.D. and Chauhan, R. M. (1997).J. Plant physio., 137:64-71.