After a few years of rice planting, there will be irregular planting. In general, this is the manifestation of mixed deterioration of rice varieties. It is necessary to know that when rice varieties are mixed and degraded, their yield, quality, resistance and adaptability will be It may be worse, which will bring some losses to rice production. Next, Xiaobian will specifically explain the reasons for this.
1. Mechanical mixing
A rice variety is often not cautious due to seed treatment, transplanting, replanting, harvesting, threshing, drying, and shipping before sowing, so that other rice varieties are planted and mixed, resulting in mixed rice.
2, natural hybridization
Natural hybridization is also a biological hybrid. It is important to know that although rice is a self-pollinating crop, it usually has a natural hybridization rate of 2% to 3%. In the offspring of natural hybrid rice, various traits are separated, so various types will appear in the same variety group.
3. Inheritance of genetic variation and traits of varieties
In general, the genetic stability of breeds is relative, while the heritability of heredity is absolute and universal. Therefore, even good traits of good varieties may undergo changes under the influence of natural conditions. In addition, there are some popular varieties, especially some varieties that have been cross-bred, which will be promoted and applied in production without being completely stable. This will definitely lead to different types. Even for those rice varieties that have been stabilized, there is always a certain proportion of heterozygous genes in the population. These individuals with heterozygous genes are not manifested in the process of breeding due to the limitation of ecological conditions. When the varieties are promoted, due to the expansion of the cultivated area, the ecological conditions of the complexes form a heterozygous heterogeneity of the varieties. Strain, that is, variation.
4, poor cultivation conditions
The characteristic characteristics of excellent varieties are formed under certain cultivation conditions and natural conditions. In the cultivation of rice, the development of various excellent traits requires certain environmental conditions. If these conditions cannot be satisfied in the long run, then it will be Mutations that cause rice varieties to degenerate.
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