Insuring against gene erosion
IN A PROGRAMME conducted by the Academy for Development of Science in Karjat in Maharashtra, farmers all over the country collected some 365 local varieties of rice in as many days. As many as 325 of these were not documented in the 60,000-long official list of the rice plant (Oryza sativa) in the country. There are believed to be more than 200,000 varieties of rice in India, but a more complete picture will be possible only after similar collection programmes are conducted in other parts of the country.
On the basis of these findings, a farmers' workshop, also conducted by the academy, has concluded that farmers are best qualified to create and maintain gene banks. Government efforts are inadequate in preventing gene erosion -- loss of genetic variability -- a factor important for plant survival, feels R H Richaria, former director of the Central Rice Research Institute in Cuttack and resource person for the farmers' workshop. If there is a gene pool, plant breeders can draw from it to develop and improve crop varieties.
The importance of having a large gene bank can be understood better when one considers the fact that only a few genetically uniform, lab-tested, high-yielding varieties have become popular during the green revolution. As they lack the hardiness of time-tested local varieties, the high-yielding ones need extra protection in the form of pesticides and support in the form of fertilisers.
According to Richaria, who has worked on rice strains for more than 50 years, collecting seeds is simple if you follow a few guidelines. In the Karjat region, seed collection begins in September with the early maturing varieties and goes on through October and November for the late maturing types. While collecting the seeds, the farmers also make an assessment of the general growth environment and physical characteristics of the plants. They also note other details such as taste and market demand. Thus, the local gene bank has all the necessary data. The earheads are carefully dried and two of them are stored for future reference. Some seeds are kept in reserve, while the rest are sown in the gene bank's fields. If the first batch does not come up well, the reserves are used.
Customs and cultural practices have played important roles in selecting and upgrading local plant varieties. Traditionally, in many parts of the country, a bride would take some paddy from her mother's home to her new home, which would be planted in the new place along with the local varieties. If the new variety yielded a good crop, it would be cultivated regularly.
Another interesting practice is seen among the Bastar tribals. Farmers of a region take paddy earheads to the community hall and sit in a circle with the grain stalk in front them. Their priest, known as the baiga, goes round in the middle, chanting and a stick in his hand. He strikes the ground in front of one of the farmers arbitrarily and the farmers all collect some grain each from the identified earhead and sow them in their fields, along with their own seeds.
Repeated cloning Richaria surmises that the priest is somehow able to identify male sterility -- a factor that prevents self-pollination and improves crops. He himself took some of the grain identified by the baiga and planted them in isolation. Not one bore rice.
Richaria feels that maintaining the growth vigour of the plant is an important aspect of crop maintenance and this can be achieved by training farmers in the technique of hybridisation. The hybridised seed must be multiplied by cloning. A plant sown in February is cloned in March. Each cloning produces 7-10 new plants. After a fortnight, the plants are cloned again. The process is continued till mid-July, that is, as long as the plant is in its vegetative state. Then they are allowed to flower and bear fruit. However, cloning is not good for routine cultivation.
Last year, the Karjat academy distributed seeds developed by hybridisation and multiplied by cloning to the farmers. The farmers were assured of full compensation if their crops failed. Each farmer was asked to return two measures of seed for every measure he received. The result: A yield of 105 kg for each kilo of seed sown. And the farmers did not have to use any chemical fertilisers or pesticides. The academy plans to repeat the experiment this year, using 18 varieties and with 150 farmers participating.