Tinkering with saffron’s genetic makeup to develop climate resilience

While there are varying reasons for the decline in production, climate change is considered a definitive one. According to a study by A.M. Husaini of the Division of Biotechnology at Sher-e-Kashmir University of Agricultural Sciences & Technology (SKUAST), unpredictable rainfall interspersed with drought is a major driver for the decline.

Saffron grows in limited areas as a niche crop. It is easily vulnerable to the impacts of climate change, potentially imperiling the livelihoods of thousands of farmers and traders.

In order to address climate change impacts on saffron production, particularly the deficit of rainfall, new saffron varieties are needed. Genetic variations or subtle changes in the DNA (in saffron in this case) can help develop new saffron varieties. But saffron reproduces only vegetatively using corms or bulbs and can’t reproduce by generating new seeds (it is sterile). This sterility doesn’t allow saffron to have genetic variations as seen in corn or other plants. Saffron cultivated worldwide is the same in terms of biological traits and varies slightly in size and shape depending upon the environment.

According to Mehraj Ud Din, a senior scientist at the Advanced Research Station for Saffron and Seed Spices (ARSSSS) at SKUAST, modifying the genetics of saffron is challenging. As it is a sterile crop, its genetic variability induction (the variations in characteristics from which the most desired can be chosen for growing improved varieties) is very low.

A 2020 study found that a large corm above eight grams produces three to four small daughter corms, which take several seasons to achieve the size and weight needed for flowering. Multiplication rates are extremely slow, and production further suffers when corms rot or become infected by diseases brought on by rodents and other sources – all contributing to commercial losses to a great extent.

Mehraj Ud Din says the inability of saffron to produce seeds is a major bottleneck in getting different variants (varieties). One can choose the varieties in other major crops according to one’s requirements. “We can do crossbreeding in the case of maize. There is a natural variability in other crops. However, it’s not the same with saffron,” he said.

The saffron grown in the valley has some natural mutants offering scope to tap those variations. Mutations are needed to get new saffron variants that are climate resilient. “Different types of mutagens are used to induce variability,” says Mehraj Ud Din.

ARSSSS is collaborating with Bhabha Atomic Research Centre (BARC) in Mumbai and BARC Zakura in Kashmir, where the material is taken and exposed to varying radiations and then returned to be implanted in the centre (ARSSSS). However, the exercise is a trial-and-error experiment. “We check which material has a good recovery rate by giving different doses to the material. But we don’t know whether we are getting any new mutants or if they only have a slight change.”

Building climate resilience using omics
To develop climate resilience, many studies on water adaptation and ideal temperatures for saffron are underway. To understand genetic variability between ecotypes of saffron across the areas of the valley where it is grown, researchers are looking for differences in adaptation to the differences in water availability.

“Currently, we are studying the water resilience of saffron by exposing it to different types of stress to see how plant growth is affected,” said Mehraj Ud Din, who opines that unusual rainfall is the primary reason for the decline in yield. “We believe there is a natural genetic variability in saffron in Kashmir. We are looking at which genotypes (varieties) will perform well under stress. If experiments yield any mutant, we study it in a controlled environment to check whether it will work.” He believes this may provide an alternative to the disturbed rainfall pattern.

Mehraj Ud Din says: “If we perform a mutation, the role of omics will be a facilitator – to identify the factor which has caused mutation. It shows which region is affected, where it is located, and how to exploit that if we go for genetic transformation.” Omics refers to a field of study in biological sciences that ends with -omics, such as genomics, transcriptomics, proteomics, or metabolomics. The ending -ome is used to address the objects of study of such fields, such as the genome, proteome, transcriptome, or metabolome.

However, he further states that omics don’t yield instant results. “We would like to have a flower of say 10-20 stigmas. But it’s not in our hands. The basic biology of saffron doesn’t permit that.”

Indoor farming of saffron is also being studied closely, particularly at temperatures required for the crop to be multiplied.

Asif M. Iqbal Qureshi, another scientist at ARSSSS, says saffron growers are keen on learning new ways to increase saffron yield. “To get more yield per unit area, we usually advise growers about saffron management, from the pre-production stage, where we tell them about the spacing, temperature, irrigation, to post-production, which includes advising them about flower picking, drying of stigmas and packaging.”

He further adds that to get more genotypes-saffron varieties that are climate resilient-mutation on a large scale is needed. Large swatches of land and significant manpower are needed to carry out the experiments in order to get desired results because one can’t predict which genotype fits well with specific climatic conditions. Qureshi says that the expectations of getting mutated genotypes are not high.

According to Mehraj Ud Din, as saffron lacks efficient mechanisms for induction, the industry is dependent on nature.

This article first appeared in Mongabay