GENETICS OF SEED COAT COLOUR IN WINTER SQUASH

LOPEZ ANIDO, F

http://www.hortres-conference.org/index.php

Conferencia; 7th International Horticulture Research Conference; 2020

College of Horticulture and State Key Laboratory of Crop Stress Biology for Arid Areas of Northwest A&F University. China

Seed colour in winter squash (Cucurbita maxima Duch.) has been long described varying from whitish to pale brown, however its inheritance has not been aproached so far (Parisand Padley, 2014 http://cuke.hort.ncsu.edu/cgc/cgcgenes/gene14squash.pdf ) This attribute has been used as a key character for the Guidelines for the conduct of tests for distinctness, uniformity and stability (UPOV, 2007 https://www.upov.int/edocs/tgdocs/en/tg155.pdf). I present here a preliminary study in order to unveil its inheritance A first cross was made between Rio Ceballos winter squash landrace, bearing brown seeds, and a zapallitotype cultivar Ferry Morse of white seeds. The F1 progeny plants were 11 of brown seeds and 13 of white seeds, fitting an 1:1 hypothesis , χc 2 = 0.16 ns)Fifteen of the F1 plants were selfed and in the following season each selfed progeny was scrutinized for seed colour in each individual plant.As we see on the Table, progenies coming from white seed plants of the F1 rendered selfed progenies enterely of white seeds in five cases and segregating 3:1 brown to white in three cases. On the contrary progenies coming from brownseed plants of the F1 rendered selfed progenies adjusting a 13:3 ratio brown to white, which is expected from a digenic inheritance of two independent loci with a dominant suppression epistasis. In this way plants of the F1 that renderedenterely white seed selfed progenies were of the putative genotype aaBB; meanwhile F1 plants of white seed that presented segregating selfed progenies of 1:3 brown to white were aaBb; and the F1 plants of brown seeds, that gave13: 3 brown to white progenies when selfed, were AaBb