In maize, fertile pollen is formed on the basis of normal cytoplasm (CITn), and hereditary sterility of pollen is due to the presence of sterile cytoplasm (CITs). The dominant Rf gene restores fertility, and sterile cytoplasm exerts its effect only in combination with the recessive alleles of this gene (rfrf). All offspring from crossing a sterile plant with a plant with a sterile cytoplasm are fertile. Determine: 1) the genotypes of the crossed plants; 2) phenotypes of hybrids obtained from crossing F1 descendants with each other.
1) Genotypes of crossed plants: (women) CIT (s) rfrf, (husband) CIT (s) RfRf or CIT (N) RfRf;
2) phenotypes of hybrids obtained from crossing F1 descendants among themselves: fertile and sterile in a ratio of 3: 1.
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