Primordia and fertile floret changes in hexaploid triticale selected disruptively for spikelet fertility

GUIDOBALDI, HA; MAICH, RH

AGRISCIENTIA

Facultad de Ciencas Agropecuarias, UNC

Lugar: Cordoba, Argentina; Año: 2002 vol. XIX p. 51 - 54

0327-6244

The main objective of this study was to measure the effect of disruptive selection of number of seeds per spikelet on primordial and fertile florets in hexaploid triticale. A divergent selection scheme was used choosing 15 F2plants with the highest and lowest spikelet fertility. During 1999 the thirty F2:5 families were sowed using one row plots 5 m long and 0.2 m apart and with 250 seed/m2. A significant direct response to selection was observed. The spike analysis by thirds showed significant changes only in the lower and middle thirds. The observed correlated responses with respect to the number of primordia and fertile florets per spikelet confirm that the plasticity of two or more characters is inversely proportional to their ontogenic proximity. From the definition of the terminal spikelet to the number of seeds determination, the number of seeds per spikelet plays an essential role as regards its positive effects on the preceding and succeeding determined traits.