Zhejiang University Scholars Have Discovered The "Quality" And "Quantity" Of The Future Cotton.

Cotton is the world's largest raw material for fiber crops and textile industry.

Cotton textiles have excellent air permeability, comfort and warmth.

At present, tetraploid cotton domesticated by humans has upland cotton and island cotton.

The yield of upland cotton is high, fiber is good, and adaptability is wide. Output accounts for more than 90% of the total cotton output in the world.

Long, strong, fine, smooth and colored island cotton, also known as long staple cotton, is the main textile material of international luxury goods. Its output is low, and it can only grow in a few arid areas such as Xinjiang, Egypt, Arizona and so on, so it is expensive.

Researchers have been trying to combine the advantages of "fish and bear paws" to breed cotton varieties with high yield, wide adaptability, and longer, stronger and finer fibers. This requires us to have a better understanding of the basis of the difference between upland cotton and island cotton in terms of yield, quality and adaptability.

Recently, Nature Genetics published online research papers from an international team led by Professor Zhang Tianzhen of Agricultural University of Zhejiang University.

This study discovered the genetic mechanism of the origin and interspecific differentiation of upland cotton and island cotton, and revealed the genetic basis of the wide adaptability of upland cotton and the quality of long staple island cotton.

Gene sequencing is an important tool in the current research field. The Zhang Tianzhen team used the DeNovoMAGIC assembly technology of Israeli NRGene company, combined with Bionano optical map, ultra high density genetic map, Hi-C and other ancillary technologies to assemble the TM-1 genome of upland cotton and the horizontal genome of the Hai7124 chromosome of self bred Cotton Varieties in China. The high genome integrity is conducive to the development of the experiment.

Comparative analysis of marine and terrestrial genome revealed that specific gene expression, amplification and chromosomal structural variation were the main reasons for the differentiation of land and sea.

During the fiber development, the genes related to membrane pport, sugar synthesis, carbohydrate metabolism pathway and other marine and terrestrial enrichment, sucrose pporters, ion pport, vacuolar invertase, and regulation of cell infiltrating substances in vacuoles and other related genes in the development of island cotton fiber lasted longer than upland cotton.

The dynamic changes of ovule fibers in TM-1 (Lu Dimian) and Hai7124 (Gossypium hirsutum L.) ovules at different developmental stages were observed after 0 days, 10 days, 15 days, 20 days, 25 days, 30 days, 35 days, 40 days after flowering.

"Simply speaking, we find that the long staple of island cotton comes from longer adolescence.

Gossypium hirsutum generally stops for 15 days, but the growth time of the island cotton is about 25 days. In the study, we found the specific reasons from the gene level.

Zhang Tianzhen said.

Another difference between Gossypium hirsutum and island cotton is the requirement for growing environment. In the previous studies, researchers have found that the upland cotton seedlings are tolerant to low temperature and high temperature.

This time, researchers found that genes that were not sensitive to cold and heat were found in the analysis of gene maps.

More ethylene and ABA signal regulated genes in upland cotton are activated to regulate the response to cold and heat stresses, which may be closely related to the wide adaptability of upland cotton.

Introgression analysis of the large fragment of A01 chromosome upland cotton revealed that there existed subtype or Xinjiang type island cotton.

Zhang Tianzhen introduced the difference between island cotton and upland cotton from the gene level, which provided strong theoretical support for the future breeding of new cotton varieties with high yield, good fiber quality and adaptability.