SHENZHEN, April 24 (Xinhua) -- A team of Chinese and international scientists has made a groundbreaking advancement in plant genetics by decoding the genetic bases of three key pea traits first observed by Gregor Mendel over 160 years ago.
This breakthrough resolves some of the longest-standing questions in classical genetics, and opens new doors for precision breeding and pea crop improvement.
The study, led by Cheng Shifeng, a researcher at the Agricultural Genomics Institute at Shenzhen (AGIS), Chinese Academy of Agricultural Sciences, was conducted in collaboration with the UK's John Innes Centre and several other institutions.
The team's findings were published in the latest issue of Nature.
"For the first time, we've identified the specific genes and mutation mechanisms behind variations in pea pod color, pod shape and flower position -- traits that had remained genetic mysteries since Mendel's original experiments," Cheng said.
In 1865, Mendel laid the foundations of modern genetics through his work on seven pea plant traits: seed shape, cotyledon color, flower color, flower position, pod shape, pod color and plant height. While later research uncovered the genetic bases for four of these traits, the molecular identities of the genes responsible for pod color, pod shape and flower position remained elusive -- until now.
Using an integrated approach combining genomics, molecular biology, bioinformatics and classical genetics, the team analyzed nearly 700 pea population samples.
They discovered that a yellow-green variation in pea pods results from disrupted regulation in the final step of chlorophyll biosynthesis. Pod shape is controlled by two independent yet functionally interconnected developmental genes. The complex flower position (fasciation) trait is governed by a gene encoding a co-receptor-like kinase.
In addition to solving Mendel's remaining trait puzzles, the researchers constructed the most comprehensive high-resolution haplotype and phenotypic variation maps for pea populations to date, covering the genetic bases of 72 agronomic traits.
"This work not only completes the story that Mendel began, but it also provides powerful new tools for genomic selection and molecular marker-assisted breeding," Cheng said. ■