Potatoes must be changed into staple grain varieties first.

To make potatoes a staple grain, whether it becomes steamed bread and noodles on the table, or into grain reserves or war reserves in the state grain depot, potatoes need to be "transformed" into whole flour first. So, can all potatoes be processed into whole flour? What kind of potatoes can be "shattered" for national food security? To this end, our reporter interviewed Jin Liping, the chief expert in the technical system of the national potato industry and a researcher at the vegetable Institute of the Chinese Academy of Agricultural Sciences.

Whole potato powder

At present, only a few varieties can be used in whole powder processing.

Using fresh potato as raw material, the fine granule, chip or powder product obtained by dehydration and drying is called whole potato powder through the process of cleaning, peeling, selecting, slicing, rinsing, pre-cooking, cooling, cooking, mashing and so on.

The state promotes the strategy of potato staple grain and makes small potatoes become the staple food on the table. It is necessary to use whole flour to make steamed bread, noodles and comprehensive utilization products, but also focus on the choice of potato high yield, whole powder nutrition, easy storage and so on. However, not all potatoes can be used for whole flour processing. At present, only a few varieties of potatoes can be used for whole flour processing. At present, the special varieties for fried food processing and whole powder processing are still dominated by foreign introduced varieties. In particular, the varieties planted on a large scale in North China for the production of raw materials for food processing and whole powder processing are basically "Charlotte" and "Atlantic" introduced from abroad. These two varieties have excellent processing quality, but due to the need for big water and fertilizer, high planting cost, small suitable area and poor disease resistance. In general, it is difficult for farmers to plant successfully.

Specialized variety

In production, most of them are edible varieties of fresh potatoes, so it is difficult to meet the demand of staple food.

Potato varieties have significant differences in dry matter content, meat color, bud eye depth, reducing sugar content, solanin content and polyphenol oxidase content, which will affect the processing quality of the whole flour. The higher the dry matter content, the higher the powder yield, the lighter color of the whole powder of sweet potato meat, the lower the production rate of more and deeper bud eyes, the deeper the color of the whole powder with high content of reducing sugar and polyphenoloxidase, and the higher the content of solanum nigrum, the difficulty and complexity of detoxification. Therefore, the varieties with shallow bud eyes, good potato shape, white potato meat, low reducing sugar content and low solanum nigrum content should be selected to produce potato powder. In addition to the above requirements of whole-flour processed varieties, the main grain varieties should also be rich in nutritional quality indexes such as protein, vitamin C, carotene and other beneficial substances.

Up to 2013, more than 430 new varieties have been bred in China, of which more than 200 new varieties have been selected and approved since 2001, including fresh potato edible type, starch processing type, fried food processing type and characteristic type. there are great improvements in yield, quality, disease resistance and appearance, but there are only 5 and 8 whole flour processing varieties. The vast majority of edible varieties of fresh potatoes are widely used in production, which is difficult to meet the needs of production and staple grain processing.

Variety breeding

There is a lack of high quality parents in domestic breeding, and 50% of the varieties that have been bred come from 7 parents.

Potato is an autotetraploid vegetative crop. The period of germplasm resources innovation and variety breeding is long. It takes 10-13 years to breed a new variety. For a long time, the potato processing industry in China is underdeveloped, potato breeding aims at high yield and disease resistance, the type of breeding variety is single, and there is a serious lack of all kinds of special varieties.

The lack of excellent germplasm resources has always been the main limiting factor for potato breeding in China. Due to the lack of long-term and stable support and the lag of resource research and improvement, the research on mining and utilization of favorable genes in related resources is still in its infancy, and there is a lack of high-quality parents in breeding. 50% of the varieties that have been bred come from 7 parents, and few breakthrough varieties have been bred. There are more than 7000 wild species, original cultivated species and local varieties preserved in the world. At present, more than 3000 resources have been preserved in only a few research units in China, among which there are a large number of duplicate resources. The serious lack of investment in science and technology leads to the backwardness, poor systematicness and low efficiency of potato breeding in China, which restricts the development of basic and public welfare research work, such as germplasm innovation, breeding technology innovation and so on.

Virus-free seed potato

At present, the coverage rate of high-quality seed potato is only about 35%, and most farmers use self-retained seed potato.

Like ordinary varieties, special varieties need to recover the characteristics of varieties after virus removal and produce virus-free seed potatoes before they can be used in production, and matched with high-quality and efficient production technology to obtain higher yield. Because the genetic linkage is difficult to break and other reasons, the disease resistance of general high-quality processing varieties is poor, so high-quality virus-free seed potato must be used in production in order to have a foundation for high yield.

At present, virus-free seed potato production has spread over more than 20 provinces, municipalities and autonomous regions across the country. According to incomplete statistics, in 2014, the production capacity of the original seed (micro potato) has reached 4.5 billion, and the actual production is about 2 billion, but at present, the coverage rate of high quality seed potato is only about 35%, and most farmers are still using their own seed potatoes.

The reason is that the existing seed potato production system is lack of planning, and most of the investment is concentrated in tissue culture and original seed production links with high labor demand and high energy consumption. however, insufficient attention has been paid to the base construction of field seed potato production, standardized production technology system and quality control technology research and development. as a result, the production capacity of miniature potato is large and the production capacity of seed potato really used for commercial potato production is insufficient. Resulting in high quality and high price of virus-free seed potato.

To speed up the promotion of virus-free seed potato, there is an urgent need to speed up the formulation of potato seed industry planning, build a clear division of labor, smooth circulation, high-quality and efficient potato seed industry system; strengthen enterprise breeding and marketing system construction, enhance the supply capacity of high-quality seed potato; establish a third-party quality inspection and testing service organization to ensure the quality of seed potato; strengthen technical training to expand potato farmers' awareness of high-quality seed potato.

Resistance to late blight

The breeding of disease-resistant varieties is like a competition between breeders and physiological races of Phytophthora infestans.

Late blight is the most important disease that harms potato production in China, which occurs all the year round in the northeast and southwest of the main potato producing areas, as well as in some parts of northwest and North China, which seriously affects the yield and quality of potato production. Breeding and planting resistant varieties is the most economical, effective and simple method to control potato late blight, but the resistance to late blight is very complex, and the physiological races of pathogens are changeable. As a result of the new physiological races, many resistant varieties and even the new resistant varieties which have just been put into application lose their resistance and greatly reduce their yield. Therefore, the breeding of disease-resistant varieties is like a competition between breeders and physiological races of Phytophthora infestans, with the in-depth study of resistance to late blight and the application of molecular biology techniques in conventional breeding, more resistant and more persistent potato varieties with better resistance to late blight are used in production.

The main grain of potato is to make efforts in the deep processing of potato, fresh food is a small part, and the production of potatoes that can be processed into whole potato powder is the core of the main grain. A few days ago, the reporter came to the research and development base in Beijing Yanqing Hisen Potato Industry Group.

In Heathon's production workshop, the reporter saw that the staff stripped the stem tip into the nutrient base in the test tube bottle under a 40-fold microscope, a process called stem tip detoxification, which is a key step affecting potato production before propagation, while in the storage workshop, small potatoes the size of one yuan are stacked in wooden boxes, which are called original seeds and will be planted in the field. Hisen Potato Industry Group is the supporting enterprise of the National Potato Engineering and Technology Research Center. it has established a virus-free potato micro-potato rapid propagation base in Yanqing, Beijing, with an annual output of 420 million virus-free micro-potatoes and a field potato breeding base of 300000 mu. Is a national leading potato production and processing enterprises. Chairman Liang Xisen told reporters that at present, Hisen has 18 varieties with independent intellectual property rights, of which "Hisen 3" and "Hisen 4" have passed the variety approval. "Hisen No. 5", "Hisen No. 6" and "Hisen No. 7" are conducting regional tests and are applying for a "birth certificate."

It is understood that at present, the potato varieties used in most parts of China are "Atlantic", "Charlotte", "Dutch potato" and other varieties introduced from abroad in the 1980s, and these varieties have been gradually eliminated abroad. there is also a situation of variety degradation in China. Kong Haiming, a technician of the Hisen Group, said that the variety of "Atlantic" is large and prone to hollow, and "Hisen 5" has solved this problem very well, while "Hisen 3" and "Hisen 4", which are mainly used for fresh food, are more prominent in output than "Dutch potato".

Over the past 10 years, Liang Xisen has been "spending money" on cultivating new varieties from real estate to agriculture. when the variety resources have a certain scale, he has repeatedly called for a change to the country. "if our country's seed potato can use better varieties, it will be a revolutionary change for the whole industry." Liang Xisen said that Liang Xisen was very excited about the potato staple grain strategy just announced by the Ministry of Agriculture, but he was always afraid that the public might misunderstand the potato staple grain, that is, fresh potatoes. He told reporters that from the strategic point of view of national food security, deep processing of potatoes is the significance of promoting staple grain, while the potato flour processing industry requires unified planting, unified management, and unified processing of varieties suitable for processing into whole flour, which is very difficult to achieve in a household of small farmers.