Leo D’Souza, Mendel of Mangaluru who worked to transform the cashew industry

On January 20, 2026, Rev. Dr. Leo D’Souza, a Mangaluru-based Jesuit scientist, died at the age of 93. Dr D’Souza, affectionately known as Father Leo, trained at the Max Planck Institute for Plant Breeding Research in Cologne in the 1960s and worked with luminaries in the field such as Ingo Potrykus, Joseph Straub and Sudhir Kumar Sopori.

He founded one of India’s oldest tissue culture laboratories in 1975, where her female-led team of doctoral students slowly and steadily made a series of breakthroughs – including the world’s first test-tube cashew tree that was transferred to soil.

Pramod Tandon, leading plant biotechnologist and Padma Shri awardee, said, “Father D’Souza was among the early pioneers of plant tissue culture research in India, making significant contributions at a time when the discipline was still in its infancy.”

In 1970, when Leo D’Souza was recalled to India after scientific studies, his PhD advisor Joseph Straub suggested him to visit a friend of his to guide him on a suitable research topic. turned out to be a friend MS SwaminathanWho was in New Delhi at that time. When Dr. Swaminathan learned that the young priest’s hometown was Mangalore, he recommended Anacardium occidentaleCashew plant as a subject of research.

tissue culture

The cashew tree is not native to India. It was brought to the coastal region from Brazil by the Portuguese in the 16th century to save the laterite soil found there from being destroyed. Once people recognized the commercial value of its nuts and fruits, it emerged as an important cash crop. By the 1980sCashew was being cultivated on about 5 lakh hectares of land in the country, although the net production was far less than optimum for the processing industry.

an article In a 1982 issue of the magazine Manushi It is noteworthy that more than 80% of the workers employed in the cashew industry are women. They were generally uneducated and routinely underpaid. Father Leo personally visited several cashew processing plants in and around Mangalore and was impressed by the condition of cashew plantation workers and small farmers. He recognized that relying on seed propagation, grafting and cuttings was not enough, and that tissue culture – a relatively new technique on which he was an expert – could be the answer. He embarked on a mission to develop high yielding varieties of cashew to benefit these sections of the society.

At the time, Mangalore already had a cashew research station at Ullal, but Father Leo was told that the scientists posted there were desperate to move as they were unused to the intense rains and severe humidity of the seaside town. Dr. Swaminathan also believed that as a Jesuit priest free from aspirations of promotion and transfer, Father Leo was uniquely placed to do justice to this neglected area of ​​research.

Convinced, Father Leo set up his own Laboratory of Applied Biology in 1975 at the Jesuit-run St. Joseph’s College in Bangalore. This was about a decade before the Department of Biotechnology (DBT) came into existence. However, five years later, he was appointed principal of another Jesuit college, St. Aloysius in Mangalore. While Mangalore was his hometown and St. Aloysius was the place where he received all his schooling, he was intimidated by the idea of ​​sidelining research for administration. Fortunately, he had a room available to move his laboratory.

Since then his laboratory has been operating there, and today it is headed by his former PhD student Sasikiran Niwas.

on top of his mind

Despite being a reluctant principal, Father Leo ran the college efficiently. From the beginning, she advocated for the inclusion of women in the college, which had been boys-only since it was founded in 1880. Not only did they have to convince skeptical management and staff, they also had to ensure that the college infrastructure would adequately meet the needs of this new demographic. In 1986, the college finally began admitting women; Today they make up more than 50% of the staff and students there.

Among the many responsibilities he took on during his career, one was particularly close to his heart: the founding and operation of the Aloysius Boys’ Home, a rehabilitation center and home for abandoned, traumatized and orphaned children, many of whom had parents in prison. He was proud of the life that the boys who grew up there had made for themselves.

In one of his essays, he wrote how driving a bus was a dream for many boys, and he was glad that many of them fulfilled it by becoming bus drivers in Mangalore. He recalled another example of a former resident of the house named Nelson, who had completed a course in vocational training and secured a job as a training officer in air conditioning and refrigeration at a technical institute.

Even though he faced administrative challenges and was involved in many other activities, his laboratory was always uppermost in Father Leo’s mind. He received approval from Mangalore University to start a PhD programme, which was (and remains) an unconventional and remarkable achievement for an undergraduate college. His first PhD student was a young woman from a village in Kundapura in Udupi district, named Aisi D’Silva.

Together they started an effort to grow tissue culture cashew plants, which would help in growing the tree faster on a large scale.

From lab to soil

Traditional breeding techniques such as seed propagation and cross-breeding can help improve plant varieties and their yield, but these are time consuming and difficult to maintain quality. On the other hand, tissue culture, aka micropropagation, allows the growth of an entire cashew plant from a small tissue sample. Controlled conditions in the laboratory allow the use of the technique collectivelyWith the guarantee that the resulting plants will be genetically identical to the parent plant.

Many scientists in tropical countries including India were trying to revolutionize the cashew industry with a reliable tissue culture protocol but this proved extremely difficult. Compared to related species such as mango and pistachio trees, cashew is recalcitrant to tissue culture, possibly because it releases phenolic compounds into the culture medium, which eventually kill the developing cells. In some cases when researchers were successful in growing plants in the laboratory, the plants died soon after being transferred to soil.

It took about 10 years, but in 1990, under the guidance of Father Leo, De Silva achieved his goal. In a paper published in the journal Plant Cell, Tissue and Organ Culture In 1992, the pair reported how they had successfully cultivated cashew plants transferred them to the soilAnd established them in the area.

Father Leo’s one regret was that he could not get the cooperation of the scientists at the Cashew Research Center in Ullal to take the work forward. He believed that this had come in the way of science fulfilling its potential with respect to cashew as well as improving the livelihoods of the people cultivating and processing it.

‘International Quality’

Over the years, Father Leo’s laboratory also did important work With coconut, fern, algae, ragi, and ornamental and medicinal plants. Apart from cashew, the team was successful in micropropagation of several other trees. Part of Father Leo’s legacy today is the avenue of tissue cultured trees growing on the campus of St. Aloysius (now a deemed-to-be university).

Many of his students went on to pursue education as well as research in industry in India and abroad. One is Smita Hegde, a leading pteridologist (teridology is the science of ferns) and currently director of research at the Center for Advanced Learning, Mangaluru. Dr. Hegde said Father Leo made sure to give his students every opportunity to present and share their work at conferences abroad. He himself had the opportunity to present his work on ferns at the Royal Botanic Gardens, Kew in 1995.

“These experiences helped us realize that our work was of international quality.” He recalled his small group of researchers hanging out on campus and feeling like “little Einsteins.”

Dr. Hegde also recalled Father Leo being a supporter of women empowerment.

“If he saw only men on stage, even for a simple function, he would ask, ‘Where is the female representation?’ Not only did he want women to have the opportunity to work, he was also keen that our work gained visibility,” she said.

used to explain himself

Although he taught at St. Joseph’s College, Bengaluru for a relatively short period, his students still remember him fondly. Notable among them is Jyotsna Dhawan, a leading cell biologist and emeritus scientist at the CSIR-Centre for Cellular and Molecular Biology in Hyderabad.

After hearing of Father Leo’s death he wrote to this reporter, “What strikes me now is that there was no contradiction between his education in the scientific discipline rooted in the principles of evolutionary theory and his identity as a man of the cloth.” “With Father Cecil Saldanha, this Jesuit botanist Gave us a strong foundation in plant science for which I am forever grateful.”

Reconciling these two identities came easily for Father Leo, but he constantly faced raised eyebrows along the way.

“When I first entered the Max Planck Institute in Cologne people stared at me,” he said in an interview with this reporter a few months before his death. “I thought they were staring at my brown skin, but it was my clerical collar.”

So Father Leo was accustomed to explain himself.

“A priest does not only have to work in the church. His work must have value for other people, especially poor people,” he confirmed in the same interview.

When one of his colleagues in Germany asked him why he did not stick to the altar and pulpit, Father Leo replied: “If Gregor Mendel (the Austrian monk often referred to as the father of genetics) had followed this principle, the scientific world would have lost an important scientist who discovered the basics of genetics and plant breeding.”

Nandita Jayaraj is a freelance science journalist and co-founder of the feminist science media project Labhopping.