Scientists keep finger on pulse

Improving the resistance of pulses would encourage more widespread cultivation swissinfo.ch

Pulses - the edible seeds of leguminous crops such as peas, beans and lentils - are an essential source of protein for millions of people in India.

Using biotechnology, Swiss and Indian scientists are trying to improve yields to meet the needs of a growing population. They believe current yields of about 620 kilogrammes per hectare could be increased as much as four-fold.

“Until now, pulses have been largely ignored,” said Katharina Jenny, programme manager of the Indo-Swiss Collaboration in Biotechnology (ISCB). “The emphasis has been on wheat and rice improvement.”

“Pulses are grown on more marginal land and yields are very low. It’s estimated that under better conditions, you could have a theoretical yield of two to three tonnes per hectare.”

Risks of the crop

“It’s a difficult crop and suffers badly from viruses, insects, fungi and stress,” said plant virologist, Dr Thomas Hohn, from the Friedrich Miescher Institute in Basel.

“In impoverished regions, farmers would rather grow rice or wheat than run a risk with pulses. The problem is that pulses are an important protein component in India’s largely vegetarian diet and you need pulses and grasses together for a balanced nutrition.”

Hohn said it was remarkable that many countries, without really understanding the science behind it, did the right thing by custom. “You have many dishes where the grasses such as rice and wheat, and legumes such as pulses, are combined – for example tacos and beans in Mexico, rice and dal in India, bread and beans in Egypt.”

With the goal of providing a better crop, Hohn is trying to develop plants resistant to viral disease.

Salt tolerance

Meanwhile, another collaborator in the pulse network, PhD student Prasanna Bhomkar, of Jawaharlal Nehru University in New Delhi, is trying to develop plants which can tolerate a lot of salt in the soil.

“I am trying to develop stress tolerant black gram plants which can tolerate a lot of salt and drought conditions because these are very predominant soil conditions in India,” he said.

Black gram is one of the four major pulse crops grown in India along with chickpea, pigeon pea and mung bean.

“If we have plants which can tolerate low water content, you can actually increase production dramatically just by increasing the area under cultivation,” said Prasanna.

“The basic idea is to develop a way to introduce a gene into this particular plant and then this particular method can be used to introduce any gene of interest. It may be a virus-resistant plant, it may be soil-tolerant or insect-resistant or vitamin-enriched.”

Minimal yield increase

Total production of pulses in India is about 15 million tonnes on a cultivated area of 23 million hectares. Over the last forty years, the increase in yield and land under cultivation has been minimal.

Meanwhile, the country’s population has grown from 550 million people in 1970 to one billion in 2000 and the availability of pulses per person has fallen from 50 grams a day in 1970 to 30 grams a day in 2000. The World Health Organisation recommends 80 grams per day to cover a person’s daily protein need.

ISCB’s pulse network includes six Indian institutes and two Swiss partners. The Swiss and Indian governments fund the programme.

Other projects, which were also approved last year, include the improvement of Indian wheat varieties and the removal of pollutants from soils.

The ISCB is simultaneously pursuing a non-transgenic approach to the problems of crop yields. For example, it is trying to produce bio-pesticides based on a fungal product. Testing is already being carried out in the field.

by Vincent Landon