GENETIC STUDIES ON SOWING-TO-HEADING AND HEADING-TO-RIPENING PERIODS IN BARLEY AND THEIR RELATION TO YIELD AND YIELD COMPONENTS

Abstract

Introduction T h e present study may be considered as supplementary to a previous work (Johnson and Alcsel, 1959), the materials and methods used being in part the same. T h e main characters here dealt with for the first time are the sowingto-heading and heading-to-ripening periods. T h e objective was to study the inheritance of these characters and their relation to the previously studied genetic behavior of yield and its components. Because of differences in dates and rates of seeding only the data on F2 generation (1958) of the 10-parent diallel cross were analysed. Materials and Methods T h e materials and methods of the present study were in part previously reported (Johnson and Alael, 1959). T h e nailles and numerical designations of the parents of 10-parent diallel cross (F: 1958) now considered are: 1. O.A.C. 21 6. Beecher 2. Hannchen 7. Sanalta 3. Proctor 8. Herta 4. Fjola 9. Velvoil 11 5. Plains 10. Huslcy Numbers 2, 3, 7 and 8 are two-rowed and 1, 4, 5, 6, 9 and 10 are six-rowed varieties. Heading dates were recorded \~.11en approximately 75% of tillers had headed. Dates of ripening were recorded when approximately 75% of the spilces and peduncles had lost all traces of green colour. As will be shown later, dominance is present for both maturity characters; therefore, F, records nude 011 the basis of 75% expression (3 do11;nant: 1 recessive) may be roughly equivalent to Fl expression (dominant). T h e analysis of the 10-parent (twoand six-rowed varieties) and of the 6-parent (exclusively six-rowed) diallel crosscs was based on Hayman (1954). T h e single array analysis for the con~binations, P I x (PI) [where P I is the recurrent parent, (P,) the set of non-recurrent parents, i = 1,2 .... ... n, j = 1,2 -------n, and j + i except for the corresponding recurrent parent included in the (Pj) set and in the offspring array as a self] is based on the following error equations: 4 Var. (cl) + r \Jar. (e,) T a r . xi, = E L , 4 Var. (d ) + Var. ( e , ) Var. TI, = E L , 2 \Jar. ( d ) + 2 Cov. (d,h) + r/n Var. (e,) Cov. s,, x, = E , , 2 Var. (d) + 2 Cov. (d,h) + l /nVar . ( e , ) Cov. F,, = E , , Var. (d ) + 2 ~ o v . ( c I , ~ ) + Var. ( h ) + r/n \Tar. (e,) + r/n (n-1) Var. (e,) T a r . x, = E S , Var. (d) + 2 Cov. (d,h) + Var. ( h ) + l / n Var. (e,) + l / n (n-1) Var. (e,) Var. F, = €6,