Durian has no thorns that makes it difficult to study

Botanists have been unable to successfully grow extremely rare thorns durian despite grafting efforts over the years.

Prickly durian was discovered more than a decade ago in Indonesia. Scientists cannot explain why this fruit exists. According to botanist Gregori Garnadi Hambali, this could be a result of a natural mutation or a recessive gene . "The incidence of thorns durian is very low, only about 1 / 1,000,000 trees," said Hambali, who works at Mekarsari Fruit Garden, a biodiversity conservation center in Bogor City, south of Jakarta, Indonesia. .

Durian fruit has no thorns. (Photo: SCMP).

The first thornless durian fruit was recorded in 2007 on the island of Lombok in eastern Bali. A smooth durian grows on a tree in a villager yard on the slopes of Mount Rinjani along with the usual berries. At first, the host family was afraid of eating durian fruit because they were worried it was poisonous. In the following season, when the tree again produced other thorny durian fruit, the landlord's son decided to taste it and discovered it smelled like a regular durian.

After listening to the report, local agricultural officials came to inspect the trees and cut the branches. They grafted a durian tree in the office yard hoping it would grow more berries. But the agricultural agency took 12 years with many grafting efforts to achieve the desired results. "Thank God. Of the 50 plants, one end gave a thorn-free durian. People are no longer saying the thorn-free durian is fake," said Maisin, head of seed certification and certification in West Province. Nusa Tenggara said.

Maisin explained that only 2% of the flowers that bloom on the tree form durian spines. The remaining flowers withered and died without fruit. The thorny durian appears to be born only when the male and female flowers of the plant are close to each other, evidence that this is a result of the recessive gene.

Durian tree without thorns on Lambok island. (Photo: SCMP).

From 50 grafted trees in 2007, the provincial Department of Agriculture has created more than 23,000 seedlings. Many trees were transferred to other provinces for planting, but none of the trees that grew on those seedlings was durian.

The expert group at Mekarsari Fruit Garden also sought to graft a tree in the center. In 2019, they planted 1,000 seedlings. Mekarsari also sells seedlings to the villagers, but only three trees grow successfully on the central campus and no trees produce durian fruit without thorns. The Mataram University's Faculty of Agriculture also tried to breed durian fruit smoothly, but it failed for four years. Every organization that has tried grafting to create durian-free durian is trying to understand the nature of the phenomenon.

"If the prickly trait is genetic, we could mass produce fruits with tissue culture. But if it's just a mutation, we can't do anything," said Muhammad Sarjan, a professor at Mataram University, said.

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