A monk’s souvenir that became pigeonpea’s crown jewel

ICP 7035, a landrace of pigeonpea from India is a rare line with resistance to multiple diseases, is hardy and a consumer’s delight. Found by chance under unusual circumstances, the landrace has shown the importance of conserving biodiversity. Though It has proved to be a worthy cultivar and parent in breeding programs, scientists say its potential is yet to be fully tapped.

ICP 7035. Photo: ICRISAT

When it was first found as an isolated pigeonpea plant nearly 50 years ago at a monk’s retreat alongside the Narmada, one of India’s longest rivers, no one knew what a fortuitous find ICP 7035 would prove to be. Among the few known lines resistant to all the major biotic production constraints of pigeonpea, this landrace has been overwhelmingly responsible for the crop’s cultivation in China, Fiji, India, Myanmar and Nepal, and it continues to be among the most-sought versions of the crop.

ICP 7035 was found during a germplasm collection trip organized by Dr Devendra Sharma who was the first pigeonpea breeder at ICRISAT. It was collected from Bhedaghat in the central Indian state of Madhya Pradesh on 8 April 1974, about two years after ICRISAT’s establishment. It was given the identification number “7035” on its arrival at the ICRISAT Genebank two months later. Pigeonpea is said to have originated in Madhya Pradesh.

Dubbed “green plague” in South Asia, Sterility Mosaic Disease (SMD) renders infected pigeonpea plants sterile and inhibits flower production. SMD is known to lay waste to entire fields. Though known for many decades, the disease’s cause, the Pigeonpea Sterility Mosaic Virus (PPSMV), was discovered only in 2000. Interestingly, ICP 7035 could resist multiple strains of PPSMV, including the virulent Bengaluru strain.

The landrace was released as cultivars in Fiji (Kamica), China (Guimu 4) and Indian states like Telangana and Karnataka where PPSMV is endemic, the authors of a recently published article note. The article pays tribute to former ICRISAT scientists, the late Drs Devendra Sharma and L Janardan Reddy, who were instrumental in ICP 7035’s discovery, by naming them authors.

Other traits of ICP 7035 that made it desirable both as a cultivar and a trait donor in pigeonpea crop improvement are resistance to stem blight, powdery mildew, halo blight and leaf spot disease. It was found to tolerate infestation by Helicoverpa pod borer and the pod fly Melanagromyza obtusa. It is a dual-purpose variety as it can be used as both a vegetable and dal (dried and split for easy cooking). When green, it packs a high soluble sugar content (around 77% higher than other vegetable pigeonpea cultivars) which is a consumer- and market-preferred trait.

The abnormal structure of ICP 7035’s flowers restricts out-crossing. Cross-pollination is a threat to genetic purity and pigeonpea is easily cross-pollinated. The landrace’s low potential to outcross adds to its attraction.

“It is important to point out that ICP 7035 is a precious genetic stock of pigeonpea. It is an ideal donor for broad-based PPSMV resistance breeding. In this context, resistant cultivars should be bred at a rapid speed for one or more biotic constraints. This can be accomplished by integrating some latest molecular tools in the breeding programmes,” the authors of the article concluded while advocating tapping the full potential of the landrace in pigeonpea improvement.

The article titled “A unique pigeonpea landrace with multiple properties” was authored by former ICRISAT pigeonpea breeder Dr KB Saxena and Principal Scientist Dr Rakesh Srivastava, and was published in the Journal of Food Legumes.

Authored by Rohit Pillandi. Rakesh Srivastava contributed to the writing of this article.