“Seedless” grapes are actually produced by drugs? Can we eat them safely?

As a common fruit available in all seasons, grapes have a strong presence in our lives. In recent years, grape varieties such as "Sunshine Rose" have become popular online. The emergence of varieties such as "seedless grapes" has satisfied the lazy people's desire to "eat grapes without spitting out the seeds".

Source: A shopping website

At the same time, the "seedless" feature has also caused some concerns among consumers. How are seedless grapes cultivated? Are they really grown with hormones? Will eating seedless grapes harm human health?

1

Why do seedless grapes have no seeds?

Seedless grapes (also called seedless grapes) can be classified into two categories: congenital seedless and acquired seedless .

Depending on the differences in their growth and development processes, congenital seedless grapes can be further divided into two types: parthenocarpy and pseudoparthenocarpy.

Parthenocarpy is the phenomenon that the ovary develops into fruit without fertilization of the ovule, which is commonly explained as a "false pregnancy". To achieve parthenocarpy, the specific process is to apply plant growth regulators to the flowers after the grapes bloom to promote the development of the ovary into seedless fruit .

Source: unsplash

Pseudoparthenocarpy is a process of "abortion of pregnancy". Through the regulation of genes and hormones, the seeds are aborted , and the fruit formed by the ovary has only very small, even negligible, seeds. Compared with parthenocarpy, pseudoparthenocarpy relies on early abortion to achieve the disappearance of "seeds".

Source: Xinhuanet

The formation of seedless grapes is caused by the "acquired environment". Generally speaking, in the absence of fertilization, gibberellins are used to stimulate the growth of grape berries, forming seedless berries.

Among the seedless grapes currently on the market, pseudomonocarpic seedless varieties account for about 85%, and are widely used in grape breeding and cultivation. Their advantage is that they "can relatively stably inherit seedlessness and other excellent traits", such as plump and large-grained fruits.

Source: Xinhuanet

2

How are seedless grapes produced?

After having a certain understanding of the acquired and acquired factors of seedless grapes, it is no longer difficult to know how to "cultivate" acquired seedless grapes. There are currently two common methods for cultivating seedless grapes.

One type is achieved through "hybrid breeding". After several rounds of hybridization and breeding, the grape fruits are able to develop normally, but the growth of their seeds is inhibited, and the wish of "only growing grapes but no seeds" is achieved.

Source: pexels

The other is achieved through the intervention of plant hormones . Specifically, there are two methods:

One is to find mutant individuals whose seeds are sterile but can produce plant hormones . For example, those plants that have mutated due to natural causes and produce seedless grapes can be preserved and then cultivated and preserved by grafting and cuttings, and finally produce seedless grapes.

The second is to use plant growth regulators and other methods to treat seeded varieties . A common intervention method to achieve seedless fruit is to treat the inflorescence of seeded grapes with gibberellins before and after the flowering period to hinder the normal development of embryos and pollen, thus producing seedless fruit. Gibberellins are a common plant growth regulator. In addition, streptomycin, chlorfenapyr, 6-benzyladenine, thidiazuron, etc. can also help achieve seedless fruit.

3

Are “seedless” grapes harmful?

As mentioned above, plant hormones play an important role in the process of seedless grapes, which has also caused people to worry about hormones. There is even a saying that "eating seedless grapes will affect fertility." So, are "seedless" grapes harmful to the human body?

In fact, the life of plants cannot be separated from the regulation of plant hormones. Many plant hormones come from the plants themselves. For example, the gibberellins mentioned above are the products of the plants themselves. 100 grams of fresh navel oranges contain 1 mg of gibberellins and 120 micrograms of auxins.

Source: A shopping website

Therefore, consumers do not need to worry too much about the safety of agricultural products that have been treated with plant growth regulators, let alone hormones. Although plant growth regulators are managed as pesticides, they are different from traditional pesticides that kill pests and weeds. There is no need to worry about the residue issues related to them . On the one hand, they are not traditional pesticide residues. On the other hand, fruit farmers use very small amounts of plant growth regulators during use, and the residues on agricultural products are also very low.

Source: Xinhuanet

"Grapes are planted on the terraces on the hillside. The dense branches and leaves spread out in all directions, like a series of green pergolas. In autumn, bunches of grapes hang under the green leaves. There are red, white, purple, dark red, and light green grapes, which are colorful and beautiful. If you go to Grape Valley at this time, the hospitable Uyghur villagers will pick the sweetest grapes for you to eat as much as you want."

Primary school text "Grape Valley"

Source: Baidu Encyclopedia

This description of grapes in the primary school Chinese textbook "Grape Valley" has become part of many children's most profound memory of grapes. Nowadays, we can buy more varieties of grapes at our doorstep, and the taste of grapes is better. This is all thanks to the hard work of agricultural science and technology workers.

To dispel the rumors about seedless grapes, let us feel free and bold to taste the lazy grapes that “do not need to spit out seeds” that have emerged with new breeding technology, bringing with us our childhood memories.