Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Gene interaction – Epistasis prepared by Dr. Paul Kusolwa • Complementary interaction = 9:7 • Dominant epistasis = 12: 3: 1 A >B • Duplicate dominant epistasis 15:1 A and B gives new phenotype • Dominant Suppression 13:3 A suppress B locus at dominant state Fruit colors in sweet pepper F2 9 Red 3 Yellow 3 Brown 1 Green Dominant epistasis – Solid fruit color in summer squash •Modified Dihybrid ratio for fruit color •12:3:1 ratio Alleles W and w for color expression W = white fruits (weak coloration), w recessive = for colored fruits At another locus Y for yellow fruits Y is dominant to y = Yellow fruits y – recessive = green fruits Dominant Epistasis - W negates the dominance of Y for color expression Both w and y when present in recessive conditions both gives green fruit color Zucchini – summer squash •selection against the dominant W alleles Fruit shapes in squash Di locus Dominant to spherical or pyriform Duplicate genes with cumulative effects When Di is present together with Spherical S locus Di is dominant = Disc fruits When Di present with recessive s = spherical fruits When didi/ss = long or pyriform fruits 9 Discs Di_S_ Modified Ratio = 9: 6: 1 1 Pyriform di/s 6 Spherical = Di/s & di/S_ Complementary interaction Pathway involving two genes Wt = warty fruits Dominant to non warty wt Hr = hard rind hr = intermediate texture 9:7 B_ Hr_ Wt_ Y_ Bicolor fruits = locus B pleiotropic for fruits and leaves For yellow and green color patches BB or Bb Extent of yellow or green dosage of another incompletely dominant, additive to modifier genes. Ep1 and Ep 2 Ep1 and Ep2 alleles are involved in enlarging the yellow patches Genotypes Bb with a dosage of 0 to 1 Ep alleles = bicolor green and yellow fruits Dosage of 2-4 dominant alleles Ep extends the yellow coloration Genotypes 9 B_Ep_ 3 B_epep 3 bbEp_ 1bbepep Extended yellow Yellow narrow Green extended green 12:4 Three or more genes interactions in ornamental gourds Gb = green bands; gb for no bands Gr/G = green rind (gr/g buff skin) L-2 = color intensity (yellow /orange) Gr Gb L-2 Ep-1/2 B_ bicolor L-2 intensity Pro ovary momo-1 Complementary recessive for loss of green fruit color before maturity mo-1 Mature orange color mo-2 Mature orange MoMo -1