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What Is Plant Variety, Plant Line, F1 Plant Hybrid
What Is Plant Variety, Plant Line, F1 Plant Hybrid

Video: What Is Plant Variety, Plant Line, F1 Plant Hybrid

Video: What Is Plant Variety, Plant Line, F1 Plant Hybrid
Video: Lecture 19 Plant Breeding 2024, May
Anonim

About seeds

growing tomatoes
growing tomatoes

Home-grown vegetable growing is, of course, different from professional farming. For better or worse, as they say, time will tell. But in both forms of organizing the process of obtaining vegetables, seeds are necessarily present.

In our farm we use high quality standard Dutch seeds, they are treated with fungicides and covered with a protective film. The last characteristic is very important.

The fact is that such harmful diseases as tobacco mosaic virus (TMV), bacterial cancer, anthracnose, black bacterial spot, and fusarium wilting are often transmitted with seeds. There is reason to believe that even late blight is transmitted through seeds - the pathogen overwinters on the seeds, in the form of oospores.

Therefore, be careful about the seeds that your "kind" neighbor gave you. Correctly disinfecting untreated seeds is a rather difficult task. We grow on our site hybrids and varieties of vegetable crops, bred by classical selection methods and genetically resistant to many diseases.

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They say there are professional and amateur seeds. If our seeds are called professional, then we are quite happy with that. Agriculture does not belong to the exact sciences, so it is difficult to give an unambiguous definition here. If we expand the topic of "amateurism", then, probably, such concepts as amateur and professional varieties will arise, but it is more convenient to develop this topic on specific examples, so let's start with growing tomatoes. This process usually starts with the purchase of seeds. I'll tell you about my own approach to my garden.

What is a plant variety. What is a plant line

Usually, a variety is a group of plants that has a complex of similar economic characteristics (early maturity, yield, fruit characteristics, etc.). These characteristics can vary greatly, for example, within one variety, some plants may have high yields, others - low, some early ripening, others late. This should be remembered by those who collect their seeds.

The varieties obtained by breeders by selecting the best plants are more uniform. For example, there is a variety of tomato Peto, breeders conducted its long-term selection, received Peto 86. The most uniform lines are. The lines are obtained by selection and long-term self-pollination of several generations of plants (usually at least 4-5). However, with prolonged self-pollination, the effect of homozygous (self-pollination) crossing was found (inbred depression - a decrease in the vitality of the plant).

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What is F1 Plant Hybrid

The problem of inbred depression was solved with the help of F1 hybrids, which are obtained by crossing two or more lines. The first generation hybrids are designated F1 (from Italian filli - children). Sometimes F1 hybrids are superior to both parents in a number of economically valuable traits (yield, early maturity, disease resistance, etc.). This phenomenon was called heterosis, and the hybrids were called heterotic. They are obtained as follows. Show pure homozygous lines. Then, individuals from pure lines are crossed with each other and it is experimentally determined, when crossing which lines, heterosis occurs.

Moreover, all F1 plants are the same in all characteristics. This can be schematically illustrated as follows. Breeders singled out 100 lines on the Peckmor variety, crossed them, and with some combination, only known to them, they got the largest Peckmor F1, perhaps even changed its name, but F1 will be present in it.

Such hybrids can be roughly called modern varieties. All of them were obtained by the method of classical selection. We plant professional varieties on the farm, i.e. those where there is a set of corresponding varietal characteristics necessary for our conditions. These signs are confirmed by the corresponding set of genes. Every living organism has its own genetic passport. Therefore, each hybrid has only its inherent qualities.

Here, too, not everything is so simple. The characteristics of the variety will appear only under certain external conditions - light, temperature, etc. They determine the necessary habitat of the organism, there are more opportunities for the influence of the environment on the manifestation of the trait. Therefore, it is very important to know what opportunities this variety has, and the ways of their implementation.

Requirements for environmental conditions for tomato:

growing tomatoes
growing tomatoes

Heat. The optimum air temperature for the growth and development of tomato is 20 … 24 ° С during the day and 16 … 18 ° С at night. Shine. For growing seedlings, the minimum illumination should be at least 8 thousand lumens, and for plants after planting - at least 10 thousand lumens. Optimal illumination - 20 thousand lumens.

Moisture. Tomato plants require low relative humidity (60-65%) and high humidity in the root environment. In the summer and spring circulation, the tomato consumes 690-750 liters of water per 1 m² (with a yield of 12-15 kg per 1 m²). Mineral nutrition: per 100 kg of products, tomato carries from 900 to 1550 g of NPK. Only under these optimal conditions will the early maturity, yield and other characteristics of the variety indicated in the annotation to it be realized. You were seduced by, say, such a characteristic of the variety as ultra-early maturity.

But you haven't looked at his other qualities at all. Your "ultra" began bearing fruit later than the mid-season, nearby growing hybrid. What's the matter? Don't believe what is written? No, the characteristic is given, maybe it’s right, just your "ultra" turned out to be either very light-loving, or with a predominance of vegetative development, and the average hybrid could tolerate shading with a generative type of development. The generative type of development excludes "fattening" of plants when grown in ground greenhouses.

Tomatoes with a generative and vegetative type of development

In short, a plant always has two principles: to the continuation of development - vegetation and to fruiting - generation. What's better? Probably, at different periods of plant life, different trends. Why do we need a tomato that bears two fruits and stops growing and, conversely, gives only leaves and flowers. These are extreme variants, in fact, different varieties have different tendencies in the genetic set, but under the influence of external factors, they show one or another type of development. I will discuss in more detail the regulation of these "tendencies" a little later. It is noticed that later varieties are more cold-resistant.

The influence of the external environment on a particular variety makes a certain contribution. It would seem that the type of tomato brush is a sign by which the variety can be determined. But at a low night temperature of 11 ° C, during the formation of the first inflorescence, the degree of branching of the brush increases; at high night temperatures, the number of flowers in it decreases. Most of the physiological characteristics (growth, stability, productivity) are hormonally regulated physiological processes that can occur under certain conditions. A well-chosen variety for your site is just a chance to get a harvest, and everything else that the plant requires is in your hands.

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