|A Regulator Controlling Both Rice Heading and Yield|
A study team, led by Prof. ZHANG Qifa, a Chinese Academy of Sciences academician with
Huazhong Agricultural University, reported in a recent issue of journal Nature Genetics its
findings on a cloned Ghd7, an important regulator in rice for both heading and yield.
The team started to study QTL in the mid 1990s, and located a QTL, or Ghd7 that has three
classes of traits determining the productivity of many crop plants. In the past 15 years, the
team has repeated confirmed the findings. Researchers isolated Ghd7 from an elite rice
hybrid, and encoded a CCT domain protein that has a major effect on a number of traits in
rice, including number of grains per panicle, plant height and heading date. Study results
show that the newly discovered gene is able to prolong heading date, and noticeably
increase plant height and grains per panicle. In the summer of Wuhan, where the test has
been made, the gene was able to postpone heading for 23 days, with an increased plant
height to 30cm, and a doubled number of grains per panicle. With a strong stalk, the plant
has registered a yield increase by 50%.
The study also shows that the gene is closely associated with the biological and geographic
adaptability of rice species. For example, both high yield hybrid rice and wild rice species in
the tropical and subtropical areas possess a Ghd7. The loss or mutation of the gene would
allow rice to grow in a higher latitude area with a shorter growth period. Apparently, the
gene plays a key role in increasing yield and having a better ecological adaptability.
ZHANG explains that theoretically, the quantity traits of a plant can be regulated by a
dominant gene. Their finding makes a good example of a gene being a regulator with
multiple traits, and creates a ground for studying the mechanism behind it. The finding will
eventually be employed to increase the yield of rice production.