1) ICRISAT pigeonpea spreads roots in China, finds multiple uses

Have you thought about eating noodles or drinking wine made out of pigeonpea (red gram)? It is a reality in China , where farmers accepted with alacrity pigeonpea varieties bred and introduced by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).

ICRISAT pigeonpea varieties reintroduced the cultivation of this perennial legume in China , and from a cultivated area of 50 hectares in 1999 in two provinces, the area under pigeonpea increased to 100,000 ha in 12 provinces in 2006.

More than the increase in the area, the innovative Chinese farmers have also found diverse uses from pigeonpea – prevention of soil erosion, crop diversification, fodder for cattle and feed for fishes, as a substrate for mushroom cultivation and lac production, as a vegetable, and for the preparation of food products. Together, these uses have made pigeonpea into a multi-purpose crop with a large and diverse portfolio of uses in China.

According to Dr William Dar, Director General of ICRISAT, the success of pigeonpea in China has shown the ability of ICRISAT scientists to develop varieties that are appropriate for the needs of Chinese farmers. This collaboration will be further strengthened when the hybrid pigeonpea, developed by ICRISAT, gets commercially launched in China.

Dr KB Saxena, ICRISAT's Principal Pigeonpea Breeder, says that though there are historical records of pigeonpea being grown and used in China , in the recent decades it had mostly disappeared from use. For centuries it was used for rearing lac insects. And when the lac industry collapsed, pigeonpea cultivation had disappeared from Chinese farmlands, till ICRISAT's improved varieties restarted cultivation.

In 1997, the ICRISAT-bred new pigeonpea material was tested for the first time in China. After the initial trials at several locations, Yunnan and Guangxi provinces were selected to conduct research on the role of pigeonpea in various cropping systems, especially for controlling soil erosion and rehabilitating degraded and eroded soils.

ICRISAT's role in the re-introduction of pigeonpea in China: the provision of suitable seed materials and production technology packages, and training of several Chinese scientific and extension staff. Subsequently, strong pigeonpea research programs were established by the Institute of Resources Insects of the Chinese Academy of Forestry in Kunming , Yunnan and at Guangxi Academy of Agriculture Sciences (GxAAS), Nanning, Guangxi.

Multiple uses

The partnership between ICRISAT and China has shown very encouraging results and now pigeonpea crop can be seen growing on the roadsides, hill slopes and riverbanks. The pigeonpea plants, especially of the perennial varieties, have a strong root system, which helps hold the soil on sloping hillsides. This quality has been used to a great extent in southern China , where more than 90% of the area is hilly.

“Pigeonpea has been found to be very successful in covering the soil and reducing soil erosion,” says Dr Zong Xuxiao, from the Chinese Academy of Agricultural Sciences at Beijing . “If perennial pigeonpea is planted after the first rains, it grows within four months and covers the ground and remains there for a few years. In comparison, any other plant capable of holding soil will take years to establish.”

“The initial reason for success of pigeonpea in China has been primarily because it did not replace any other crop, and has been used to get productivity out of wastelands,” adds Saxena. However, once the crop stabilized the innovative Chinese farmers found multiple uses for the hardy legume.

The Chinese farmers have intercropped pigeonpea successfully with cassava and banana. The tender stem and leaves of the pigeonpea plants are being used as fodder for cattle, sheep, rabbits and even as feed for fish in ponds. The waste from the plants is being successfully used as substrate for growing mushrooms. The traditional use of rearing lac insects on the stem of the pigeonpea plant also continues. China also started test export of vegetable pigeonpea in 2006.

At present, efforts are also being made to popularize pigeonpea for human food, especially as green peas. Chinese food technologists have developed a number of snacks, food items, and drinks using dry and green seeds of pigeonpea. The preparation of pigeonpea noodles is a case in point.

Growing further with hybrids

There is also potential for increase in production when the hybrid pigeonpea varieties, developed at ICRISAT and waiting for commercialization in India , make their way into China . According to Saxena, there is already interest among Chinese seed companies to product hybrid pigeonpea seeds for the Indian market.

The hybrid pigeonpea, which is at the threshold of commercialization in India , holds the potential for launching a pulses revolution in India , according to Prof MS Swaminathan, eminent agricultural scientist and Chairman of the Indian National Commission on Farmers. In a recent interview to Vijay Times, he listed ICRISAT's breakthrough with developing the first hybrid pigeonpea as one of the most notable achievements in agricultural research in 2006.

Prof Swaminathan said that the development of hybrid pigeonpea strains capable of yielding 3 to 4 tons per hectare is a major breakthrough for 2006. These hybrids are “capable of launching a pulses revolution just in the same way as the semi-dwarf varieties triggered the wheat and rice revolution in the sixties.”

The long cherished goal of pigeonpea breeders has been to break the yield barrier in the crop. The productivity has remained low in spite of releasing over 100 varieties. Therefore, the alternative breeding approach such as hybrids, which has been effectively used in many crop species, was attempted for enhancing yield. The hitch though was that there was no technology for developing male-sterile lines in pigeonpea.

Male-sterile plants are those that do not have functional male sex organs. Hybrid production requires a female plant in which no viable pollen grains are borne. The expensive and labor-intensive method is to remove the male organs (anthers) from the plants. The other simple way to establish a female line for hybrid seed production is to identify or create a line that is unable to produce viable pollen. This male-sterile line is therefore unable to self-pollinate, and seed formation is dependent upon pollen from the other male ferrtile line.

ICRISAT began research on this breeding approach in pigeonpea in 1974. ICRISAT along with the Indian Council of Agricultural Research (ICAR) released the world's first genetic male-sterility (GMS) based pigeonpea hybrid in 1991 (in GMS technology the factor for male-sterility is in the nucleus of the cell, and upon multiplication produces only 50% male-sterile offsprings). This was followed by the releases of five additional GMS-based hybrids. These hybrids performed well and in spite of their 25 to 40% superiority in yield they could not be commercialized because of their tedious and inefficient seed production technology.

These developments, however, encouraged ICRISAT to breed a more efficient cytoplasmic-nuclear male-sterility (CMS) system that would overcome the seed production bottlenecks of GMS-based hybrids (the factor for male-sterility is in the cytoplasm – the fluid outside the nucleus in the cell – thereby 100% of the offspring are male-sterile).

In the recent years, ICRISAT has made a significant progress in developing efficient CMS systems using the cytoplasm of the wild relatives of pigeonpea. Among these, one CMS system, derived from Cajanus cajanifolius is being used in developing the new generation of pigeonpea hybrids. A number of new experimental hybrids have exhibited 30-100% hybrid vigor for seed yield.

So far the progress in the mission of breeding high-yielding CMS-based pigeonpea hybrids has been tremendous and ICRISAT's pigeonpea team believes that the reality of commercial hybrids is just around the corner.

When the ICRISAT-developed hybrid pigeonpea seeds reach China , the pigeonpea cultivation in the country will increase substantially, increasing the popularity and use of the legume that crossed the border as a plant that could help control soil erosion.

For further information, contact Dr KB Saxena at k(dot)saxena(at)cgiar(dot)org.

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