CRISPR crop of one-step hybrid seed production possible

in the past few decades, crop hybridization technology greatly improves the global yield. However, the design and maintenance of the hybrid production line has been very complicated and laborious. Now, Chinese researchers have developed a new system, the CRISPR-mediated genome editing with other methods combined, with the conventional hybridization method can be compared to produce better seeds, and the production time is shortened 5 to 10 years. The study was published in the 7 May 8, the molecules of the plants of the magazine.

in crop production, mongrel than thoroughbred. With a Pro camera than the hybridization of the two genetic distance of plant varieties will usually produce a fine trait of the offspring. Offspring tend to have higher yields and better disease resistance. This phenomenon is called hybrid vigour or heterosis.

Chinese Academy of Agricultural Sciences, senior author Xie Chuan Xiao said:“however, the current mixing method is very time-consuming and cumbersome.”

for example, to produce hybrids is the first step in looking for or generated with a mutation of the parent plant, so that it does not produce viable pollen. This is to avoid self-pay, and to ensure that most of the parent plants are available through different varieties of fertilization. But children need fertile, in order to be able to self-hybridize to produce more of itself and as the parent plants. Scientists will make such a sterile plant with another species having genetic fertility of plant hybridization, in order to restore the plant’s sterility and production of hybrid seeds. The establishment of such a production cycle for the in the field the establishment of efficient seed production is critical.

these methods on the plant genotype have very special requirements, the establishment of a stable sterile and fertile varieties may take several years.

Xie said:“these limitations restrict their use in commercial agriculture in a wide range of applications.” “But we use CRISPR / Cas9 to the new system can significantly simplify the process. Now, just one conversion you can.”

Xie and his colleagues first constructed a maize fertility gene MS26 Cas9 carrier. They also prepared a second carrier, known as MGM’s. The first carrier by cutting off the MS26 a fragment of a work, the Fragment will allow the plant genetic infertility. MGM carrier with three functional parts: the recovery of fertility effective MS26 gene coding sequence, so that the pollen inactivation of the enzyme and the seed in the display of the red mark.

the team will be two vectors are introduced to Agrobacterium, and with its transformed corn embryos. Because maize is a diploid, that is each gene has two copies, so these edited embryonic in addition to the introduction of a single copy of the MGM gene, will also carry two copies of the mutated MS26 it.

these plants are self-crosslinking, according to meiosis rule produces two types of offspring, their ratio of 1: 1: one having MS26 and MGM mutation, the other having a MS26 mutant and not MGM’s.

no MGM progeny are infertile, and therefore can be used as hybrid seed production of Pro-in the present. Because these parents did not carry the exogenous MGM genes, so their offspring(if with non-genetically engineered varieties hybridization)is not transgenic.

with MGM offspring of the other half with MMG, and the current presence of the MGM offspring is fertile, and substantially with their parents the same. These plants(known as maintenance of plant)can be self-hybridization, so that the sterile plants to produce hybrid seed and more to maintain the plants.

maintain agent and also with from the MGM vector expressing the red fluorescent marker, and therefore can easily combine them with a sterile seed to distinguish and classification.

“our system greatly reduces the construction of stable hybrid seeds production line of the required resources. Therefore, the seed input and the cost will be greatly reduced,”he said.

in addition to corn, many other major crops also has the MS26, including rice, millet, wheat and sorghum. Therefore, this new method can be easily applied to other crops, and even can be applied to crops in other decisions of the fertility gene.

“from a technical point of view, we from large-scale app not far. However, in obtaining approval for commercial production beforeWe need to go through a program.”