"contraceptive with seedless grapes" is pure nonsense.

It's time to eat grapes, but recently a video has spread so much on Weibo and Wechat that many people are deterred from looking at grapes. In the video, a man who looks like a "fruit farmer" is carrying grapes while talking to the photographer, saying that the seedless grapes are "dipped in contraceptive." As the video was forwarded and spread, some seedless grape producing areas were exposed by the media that sales had been affected. How are seedless grapes grown? Is it really caused by dipping it in contraceptive? Will eating seedless grapes harm your health? A reporter from People's Daily's "Verification" column conducted a visit and investigation.

Can contraceptive make grapes seedless?

Response: interviewed fruit farmers have never heard of this practice; experts say human use of contraceptive has no effect on plants

In the online video, the "fruit farmer" repeatedly mentioned "contraceptive" and answered the photographer's question that "seedless grapes dare not be given to children". "it must have an impact if you eat it."

On Sina Weibo, an official verified account named "Shijiazhuang Information pass" revealed that the video took place in a picking garden near Shijiazhuang from fans. His family learned the "inside story" from fruit growers in the picking garden on Aug. 27.

The reporter contacted the Weibo operator on Sept. 11 to ask where the picking garden in the video is and whether he can contact netizens who broke the news. The blogger replied: "he refused to be interviewed." Currently, through Weibo search, netizen "Sun Mask" first posted the video on Weibo on Aug. 27. The netizen replied on Sept. 11: the video is provided by netizens. "the rumor has been refuted, and the claim of the fruit grower is not entirely true."

In order to find out the truth, the reporter came to several major grape producing areas around Shijiazhuang, Hebei Province. Local farmers watched the video and said that the accent of the "fruit farmer" in the video is like a local accent, but it needs to be further confirmed.

In Susheng Village, Donglizhuang Town, Jinzhou City, Li Cangying, a big grape grower, said he had never heard that contraceptive could produce seedless grapes. The reporter asked agricultural technicians and township cadres in Jinzhou, and they all said they had never heard of this practice.

Can contraceptive produce seedless grapes?

Kui Rong, director of the second outpatient clinic of the Reproductive Medicine Center of Shijiazhuang Obstetrics and Gynecology Hospital, said that only after entering the human body can contraceptive be recognized by the human response recognition mechanism, and then adjust various physiological indexes in the body to achieve the purpose of reducing the effect of pregnancy. Due to the lack of corresponding receptors and signal pathways in plants, contraceptive, as an animal hormone, can not be recognized and effective by plants, so it is impossible to give plants "contraception" at all.

"the idea of dipping in contraceptive is ridiculous." Nie Jiyun, director of the Institute of Fruit trees of the Chinese Academy of Agricultural Sciences and the risk Assessment Laboratory of Fruit quality and Safety of the Ministry of Agriculture (Xingcheng), said that the growth regulators used by plants are commonly known as "plant hormones," which are completely different from the molecular structure of animal hormones, and the structure and proteins carried by plant and animal cells are also completely different. Contraceptive can not make fruit seedless, plant hormones can not regulate human growth and development.

How are seedless grapes cultivated?

Response: some use gibberellin and other plant growth regulators, and some use mutant individuals to produce, which is no different from normal fruits in nutrition.

According to Ji Huicun, director of the Fruit Tree Station of Shijiazhuang Forestry Bureau, fruit seeds (that is, seeds) are developed from plant ovules, while fruits (that is, pulp) are developed from ovaries. In the process of fruit growth and development, seedless fruit can be cultivated if the ovule development is inhibited and the ovary development is not affected.

According to reports, at present, there are three common cultivation methods of seedless fruits. One is to use plant hormone treatment to inhibit seed growth and promote fruit development; the second is to transform diploid plants that can produce seeds into triploid plants through hybridization, hindering the normal development of seeds and giving certain stimulation at the same time. So that the fruit itself can produce enough plant hormones for its development to promote fruit formation. Seedless watermelons are obtained in this way; the third is to produce seedless fruit by looking for mutants that produce sterile seeds but can produce their own plant hormones.

According to Huicun, seedless grapes are typical examples of the first and third types of seedless fruits. For example, if Jufeng grape with the largest cultivated area in China is treated with gibberellin at full flowering stage and young ear formation stage to inhibit seed development and promote fruit expansion, seedless Jufeng grape can be obtained. Due to the variation of grape varieties such as "Jingkejing" and "Da Grain Red Seedless", the fertilized embryo sac will stop developing soon after pollination, but the fruit itself can produce hormones, which makes the fruit expand and develop into seedless fruit. "in terms of nutrition, there is no significant difference between seedless fruits and normal fruits." Drama Hui Cun said.

"the grapes planted are not only sold, but also eaten by themselves." Liu Li, a fruit farmer in Dushe Village, Tiegan Town, Shenze County, Shijiazhuang City, has been growing grapes for nearly 20 years. "for example, the variety Xia Hei, which is treated with gibberellin during flowering, will become seedless grapes, which many villagers know." Liu Hongbo, a fruit farmer in Dushe village, said: "Plant hormones are convenient and cheap to use. It's not necessary to use contraceptive at all."

Nie Jiyun introduced that gibberellin is the most commonly used plant growth regulator in grape seedless cultivation and has been legally registered for grape production. Gibberellin is a natural plant hormone, which was discovered by Japanese scientists in the study of scab infection in rice plants in the 1930s. Later, researchers carried out large-scale production by fermentation or artificial synthesis, which was used in potato, tomato and other crops to promote growth, germination and improve fruit setting rate.

Is gibberellin harmful to the human body?

Response: gibberellin is extremely low toxic and easy to degrade; according to EU standards, it may be affected only if adults eat about 1.8 tons of residual gibberellin grapes per day.

As "contraceptive" and "seedless (son)" are easy to cause association, many netizens said, "never dare to eat seedless grapes again." Will the "plant hormones" used in seedless grapes remain and have an impact on the human body?

Wang Zhongyue, a researcher at the Institute of Plant Protection of the Chinese Academy of Agricultural Sciences and director of the National Grape Industry Technology system Pest Prevention and Control Research Office, said that plant hormones are a kind of substances contained in plants themselves and can regulate plant growth. Similar substances can also be synthesized artificially. As long as it is used scientifically, it will increase production. Even if it is not used scientifically, it will only affect the quality, storage and transportation of crops, shelf life, etc., and will not affect food safety. For this kind of agricultural materials, the Ministry of Agriculture has proved through a large number of scientific experiments that it does not cause harm to human beings, animals and the environment.

Ji Huicun said that even if gibberellin and other plant hormones are eaten by people, they will soon be excreted out of the body with metabolism and have no adverse effect on the human body. What's more, there are a lot of plant hormones naturally produced in plants, and there are no health hazards after eating them.

"just as animal hormones cannot act on plants, all kinds of plant hormones used in agricultural production cannot regulate human growth and development even after ingestion." 'so you don't have to worry about affecting the development of children, 'she said.

Nie Jiyun explained that the concentration of gibberellin used in grape cultivation is very low, and if the concentration is high or the dosage is high, it will cause damage to the plant. Moreover, it takes two or three months from the application of gibberellin at flowering stage to grape harvest, and the previously sprayed gibberellin is basically degraded.

In practice, it has also been found that excessive use of plant growth regulators will sometimes cause abnormal plant growth, deformed melon strips, twisted leaves, brittle stems and other problems. However, these are the effects on plants, and no cases of harm to the human body have been found.

Fruit grower Liu Li even said that the use of gibberellin is very small. "if you use too much, the fruit branches will harden and the peel will become thinner, which is not conducive to long-distance transportation."

Wang Zhongyue also said that gibberellin toxicity is extremely low. Many countries in the world exempt compounds that do not affect food safety after use. China is using international experience for reference to discuss the exemption standards of some plant growth regulators, including gibberellins. The reporter inquired about "gibberellin" in the "maximum Pesticide residue Database" on the official website of the Pesticide Control Institute of the Ministry of Agriculture, China Pesticide Information Network, and showed that in the United States, Japan, Australia, South Korea, New Zealand and the International Codex Alimentarius, only Japan has stipulated the maximum residue value of gibberellin at 0.2 mg / kg (the website showed that the data was updated on May 29, 2012). Gibberellin is not involved in the maximum residue limits for pesticides in Food (GB2763-2014) issued by the National Health and Family Planning Commission and the Ministry of Agriculture.

Nie Jiyun said that at present, the EU standard for the non-visible harmful effect of gibberellin is 3 mg / kg per day, that is to say, for an adult with a body weight of 60 kg, 180 mg of gibberellin per day may have an impact on health. According to the results of grape quality and safety risk assessment of the Ministry of Agriculture of China for many years, gibberellin is rarely detected in grapes, and the residue in the samples is less than 0.1mg / kg. According to this numerical calculation, people with a body weight of 60 kg have to eat 1800 kg of gibberellin residual grapes a day in order to ingest 180mg gibberellin.