At first, they thought it was due to a lack of nutrition in the wild, but they worked water and fertilizer, and the problem of fruit drop still did not improve significantly. Just when they suspected that it was a virus or a deficiency of some trace elements or something else, it happened that Hu Weidong came to the Tropical and Subtropical Plant Research Institute to inspect the work, Cai Xitao thought of Hu Weidong's various legends, and immediately bluntly explained the problems encountered in the research to him, but Hu Weidong's answer sounded a little layman, "I don't know much about plants, if there is no problem with water and fertilizer, is it a pollination problem, it seems that many introductions and domestication in history have been hindered because of this"

"There is also this problem in the wild, if it is caused by incomplete pollination, it means that its pollination mechanism itself is problematic, then isn't the evolution of this species a failure? How did an evolutionary failed species survive to the present? A college student whose newborn calf is not afraid of tigers immediately retorted.

Hu Weidong didn't get angry because he was confronted, but he still shook his head with a smile and asked, "Who said that evolution is only successful?" ”

"But from the point of view of evolution, shouldn't species that fail evolve be eliminated?" , The graduate student was strong, and continued to stiffen his neck despite Cai Xitao's instructions.

"Who said that? There are more species that fail to evolve but still live well, and as long as the defects are not fatal or seriously affect their survival competitiveness, the species can continue to continue. According to your point of view, we humans are the most evolved animals at present, shouldn't there be any evolutionary failures? All right. I ask you, isn't it an evolutionary failure that the vast majority of animals have the ability to synthesize vitamin C, but we humans have lost this function? Hu Weidong casually gave an example to educate the young man in front of him who was reading a dead book.

"That's true, but weishenme?" , the young man knows his mistakes and corrects them, but his face is still full of puzzlement.

Cai Xitao's knowledge and experience are far from being comparable to his disciples. When I heard this, I understood. "I understand what you mean, Dean Hu, that evolutionary failure does not necessarily mean that a species cannot be sustained, depending on the extent of its impact. Pollination difficulties, while a major drawback, are not completely impossible. Therefore, it will only reduce the seed setting rate. And not completely unsturdy. So it can still reproduce. In this way, it is really possible that this oil melon has fallen fruit due to pollination difficulties! ”

To test whether this idea was correct, Cai Xitao and his disciples began experimenting with artificial pollination. As a result, even the artificial pollination on the jishu, which is still very immature, has greatly reduced the fruit drop rate of oil melons, and the facts have fully proved that Hu Weidong's previous guess was correct. With the continuous improvement of artificial pollination by Cai Xitao and others, the fruit drop rate of oil melon has been declining, and this new oil crop finally has a large number of promotion value, and later the varieties of oil melon have been continuously optimized and improved, and its oil yield is almost second only to the oil palm tree known as "Shijie Oil King", and its quality is much better than palm oil, which is almost no benefit to the body, and has gradually become the most important oil crop in the subtropics and tropics, which is very different from its historical situation (Note 1). I have to feel that even if it is a crop, whether it can come out depends on luck

But that was many years later, in 1943, when the oil melon had just begun to be promoted, Cai Xitao and his team were able to win the award, mainly because of their improvement of artificial pollination, this achievement has a very wide impact, and it is fully worthy of Hu Weidong's high praise.

Of course, the discovery and domestication (in fact, artificial cultivation or breeding) of valuable wild species is also very meaningful, but the oil melon is only one of them, and Cai Xitao is not a pioneer, so his contribution is far less significant than his improvement of artificial pollination.

In addition to oil melons, Hu Weidong believes that the most valuable domesticated and domesticated plants mainly include kiwifruit, breadfruit, eucommia, oil nan, kelp, stone cauliflower, chlorella, spirulina and more than ten species, and animals include sika deer, river crabs, bees, ash worms, shellac scales, turtles, small civets, forest musk deer, etc., these projects have provided or will provide more food, medicinal materials or special industrial raw materials for the Chinese people, in addition to parasitic wasps for biological control and sea buckthorn to improve the environment. Perhaps the level of biological science in China is not as good as that of the Western powers for the time being, but in terms of application, Hu Weidong can confidently claim that China has reached the advanced level of shijie.

In addition to the domestication and utilization of wild species that have been discovered, China has also introduced many foreign species in recent years, such as sugar maple, balsa wood, giant algae, etc., among which there are even new species discovered abroad by Chinese scientists after going abroad, such as stevia, which are also of immeasurable positive significance for China's economic construction and the lives of Chinese people.

However, in view of the lessons of so many ecological disasters in history, Hu Weidong has been very strict about the introduction of foreign species, for example, some people tried to introduce water hyacinth (water hyacinth) on the grounds of purifying water and using it as feed, but Hu Weidong was stuck. Because although the hyacinth can absorb heavy metals, the heavy metals still remain in its body, which is of little practical significance; The dry matter content is too low, there is no nutrition, although the pig can eat, but it is very reluctant as feed; What's more, water hyacinth reproduction speed is extremely fast, it is easy to cover a large area of water, and its growth will consume a lot of dissolved oxygen, so it will seriously affect the growth of underwater organisms, and it is extremely time-consuming and laborious to clean up, so the introduction of water hyacinth is definitely more than worth the loss

In addition to the fact that each species to be introduced needs to be carefully studied and analyzed for its possible harm, Hu Weidong also proposed the so-called "three principles"

Note 1: Historically, because of the late domestication of oil melons, the yields of other oil crops were higher at that time, it was naturally difficult to obtain sufficient competitiveness, and more importantly, the area of China's Asian belt was very small, and most of the arable land was occupied by the more important natural rubber and sugar cane, so it was not worth a large long-term investment in this project, as for other countries with wild oil melon distribution, there is no such scientific research capacity. At this time, however, China has acquired a large tract of tropical and subtropical arable land in the Indochina Peninsula, and the situation is naturally completely different. (To be continued......)