Allelism between the P and Stp Genes for Seedcoat Color and Pattern in Common Bean
2003; American Society for Horticultural Science; Volume: 128; Issue: 4 Linguagem: Inglês
10.21273/jashs.128.4.0548
ISSN2327-9788
Autores Tópico(s)Plant Gene Expression Analysis
ResumoThe P locus in common bean ( Phaseolus vulgaris L.) can express complete absence of color (white) in seedcoats and flowers with p (with B V ) or a pale grayish white seedcoat and nearly white flower with p gri , but P has never been considered a seedcoat pattern locus. Genes controlling seedcoat colors and patterns have been backcrossed into the recurrent parent 5-593 with black seedcoats and violet flowers. The cross, p BC 3 5-593 × t stp mic BC 3 5-593 (black seeds with a long white micropyle stripe and fibula arcs), failed to show evidence of genetic complementation in either F 1 or F 2 progeny, leading to the hypothesis that P and Stp are allelic. Five cross combinations between two recessive P alleles ( p BC 3 5-593 and p gri BC 3 5-593) and three recessive alleles at the stippled seedcoat gene Stp ( stp BC 3 5-593, stp hbw BC 3 5-593, and stp mic BC 3 5-593) expressed no genetic complementation in seedcoats and flowers of F 1 progeny and confirmed the allelism hypothesis. New gene symbols are proposed for the recessive alleles at Stp , viz., p stp for stp , p hbw for stp hbw and p mic for stp mic . The dominance order at P is P > p mic > p hbw > p stp > p gri > p . Crosses were made between t self-colored BC 3 5-593 and three other parents— p stp BC 3 5-593, p hbw BC 3 5-593, and p mic BC 3 5-593—to explore interactions between the pattern genes T and P ; and segregation for seedcoat patterns in F 2 was discussed. The hypothesis was proposed that the T locus regulates expression at P , or the biosynthetic step regulated by P .
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