A rye crop grown on heavily degraded grassland at an altitude of 3,900 meters in Tibet.
A rye crop grown on heavily degraded grassland at an altitude of 3,900 meters in Tibet.
Rye has a strong ability to adapt to bad conditions in nature, which fascinates many breeders.
Recently, the Agricultural College of Henan Agricultural University has solved this problem by many universities and scientific research units within the United Nations, completed the assembly of the fine map of the rye genome, and revealed the uniqueness of the structure and evolution of the rye genome and its starch synthesis, storage protein, The genomic characteristics of related genes such as heading date and domestication.
Build high-quality detailed maps
Build high-quality detailed maps Cultivated rye belongs to the genus Triticeae of the Gramineae family.
Rye can be described as a "dark horse" of the wheat tribe, because rye can still grow under extreme soil and climatic conditions.
"For example, high altitude, cold, poor soil and other conditions, rye can thrive.
"Triticale cultivated with rye as the parent has both the environmental adaptability of rye and the potential of wheat production.
Moreover, as a species between wheat and barley, rye is also very important in evolutionary status.
This is not easy.
"Although the rye genome has only 14 chromosomes like other diploid wheats, it is nearly 8 Gb in size, 25 times that of rice, 4 times that of maize, and 1.
"The protagonist" selected the Chinese cultivar "Weining Rye" provided by Sichuan Agricultural University.
Wang Daowen (left), Li Guangwei (middle) and Yang Jianping observe the heading characteristics of "Weining Rye".
Wang Daowen (left), Li Guangwei (middle) and Yang Jianping observe the heading characteristics of "Weining Rye".
"This is the most complex diploid gramineous species genome assembled in the world.
The origin and domestication of rye
The origin and domestication of rye With the sequencing results, the entire evolutionary history of rye can be explored.
"Rye was originally a weed, similar in morphology to wheat and barley.
Therefore, it avoided being removed as a weed in the field.
Later, due to its outstanding drought resistance, cold resistance and disease resistance, it spread in wheat and barley.
It is gradually domesticated to form such a special wheat crop.
” According to Li Guangwei, the co-first author of the paper and a Ph.
D.
from Henan Agricultural University, by analyzing the domestication sites of the entire rye genome, they found that some genes can analyze cultivated rye.
The domesticated genome features provide a molecular mechanism for the mimicry evolution hypothesis of rye.
There are several important time points in the evolution history of rye.
The common ancestor of rye, wheat, and barley diverged about 9.
6 million years ago to 15 million years ago.
In Yang Jianping's view, compared with wheat and barley, rye has a relatively low degree of domestication and is considered "semi-domestic", so rye has many primitive genes left.
Nature has gone through a very complicated selection process, coupled with the struggle and choice of plants themselves, "coincidentally" created today's rye species.
In this complex diploid gramineous plant, researchers have also identified more than 20,000 gene duplication phenomena.
They compared the gene duplication of rye with those of wheat and barley and found that during the entire evolution of rye, there have been two significant genome expansion events.
"One time occurred about 1.
7 million years ago, which was close to the expansion time of barley; the other time occurred about 500,000 years ago, which was similar to the expansion time of tetraploid wheat.
" Li Guangwei said, on the evolutionary road, cultivating rye The genetic diversity is also declining.
In Li Guangwei’s view, gene duplication can generate new resources for the differentiation of new gene functions, and it can provide a necessary foundation for the adaptive evolution of species under different conditions.
This explains to a certain extent why rye can be used at some extremes.
Under the conditions, it has outstanding resistance and strong adaptability.
Locate functional genes and analyze agronomic traits
Locate functional genes and analyze agronomic traits Around the world, more than 61.
8 million mu of planting area produced 11.
2 million tons of rye.
Asia contributes 13% of global rye production, of which 50% comes from China.
Rye is very important.
It is not only a crop in itself, but also provides one-third or one-fourth of the genome of triticale, a new species of artificially synthesized heterohexaploid and octoploid.
"Triticale is a very valuable crop.
It is a species that does not exist in nature and is produced by the artificial hybridization of rye and wheat.
It combines the high-yield characteristics of wheat and the ability of rye to adapt to extreme environments.
"Wang Daowen said that the biomass and grain yield of triticale are much higher than that of rye, and it is widely cultivated worldwide.
Yang Jianping introduced that the world has a very high proportion of wheat varieties that have a "blood relationship" with rye.
At present, about 50% of wheat varieties in China carry the chromosomes of rye, and this type of wheat occupies a dominant position in the northern winter wheat region and the Huanghuai winter wheat region.
.
The 1BL/1RS translocation line produced by a distant cross between rye and wheat can significantly improve the disease resistance and yield of wheat, and play a vital role in ensuring wheat production and food security in my country and the world.
A total of 45,596 high-confidence genes have been annotated in "Weining Rye" this time, among which 1989 are disease resistance-related genes.
Next, the researchers will also dig out the excellent genes of rye tolerant to barrenness, drought, and cold.
"We can more accurately use molecular markers to assist breeding, purposefully transfer the excellent genes of rye to wheat to play a role, and provide substantial help for wheat genetic improvement.
" Ren Tianheng said.
"This time, we have also found some genes behind the domestication of rye, such as genes that promote early flowering.
All crop breeding hopes to appropriately shorten the growth period of the crop, and to bloom and mature earlier while ensuring yield, so as to avoid the late stage.
Natural disasters in China can also save more time to prepare for the planting of the next crop.
” Wang Daowen said, taking wheat in the Huanghuai wheat region as an example, early maturity can avoid the heat or heavy rain in June.
Among the many special traits of rye, some are related to quality, such as starch synthesis and storage protein, which are very important.
"During the evolution of the rye genome, the starch synthesis pathway genes have undergone multiple replication events.
There are 9 starch synthesis genes in'Weining Rye' that have replicated, and the expression of the replicated genes will change, possibly in the grain.
Play different functions during development.
" He Hang, the co-first author of the paper and a researcher at the Institute of Modern Agriculture of Peking University, told China Science Daily.
Seed storage protein has a decisive influence on the processing and eating quality of wheat crops.
"Unlike the extensive duplication of starch synthesis pathway genes, the rye storage protein gene has undergone partial gene deletion compared with wheat and barley.
" He Hang pointed out that, such as low-molecular glutenin, there is also a part of gliadin, which is possible Reduce the viscosity of the dough; these deficiencies also promote the synthesis of high molecular weight glutenin, which can lead to an increase in the strength of the dough.
These findings can help improve the quality of rye, wheat, and triticale.
Related paper information: https://doi.
org/10.
1038/s41588-021-00808-z
This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only.
This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of
the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed
description of the concern or complaint, to
service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content
will be removed immediately.
