Genetic Analysis of Grain Yield, Grain Yield Components and some Phonological Traits of Triticale Genotypes

Triticale is a crop species resulting from a plant breeder''s cross between wheat (Triticum) and rye (Secale). Plant breeders originally wanted to include the combination of grain quality¡ productivity¡ and disease resistance of wheat with the vigor and hardness of rye. Triticale is mainly introduced as a crop which is more adapted under low-potential condition than the wheat and other small cereals. Triticale could be used as a feed grain. As a feed grain¡ triticale is already well established and of high economic importance. The aim of a triticale breeding program is mainly focused on the improvement of quantitative traits¡ such as grain yield¡ nutritional quality and plant height¡ as well as traits which are more difficult to improve¡ such as earlier maturity and improved test weight. In order to study the relationship between grain yield and its related traits and to select high yielding lines of triticale¡ this research was carried-out in a low-potential condition.
Material and This research was conducted in Ahvaz Agricultural Research station during 2013-2014 cropping season¡ with 36 lines¡ using α-lattice design with two replications. Fertilizers were used based on soil test results. Each line was planted in six 6-meter rows with 0.2 meter spacing in Nov.8 and irrigation was done immediately. Days from germination to heading¡ physiological maturity and ripening stages¡ and grain yield and its components were determined. Genetic variation coefficient was calculated based on GC={[(Vg-Ve)/r]/M}×100¡ equation in which GC¡ Vg¡ Ve¡ r and M are genetic variation coefficient¡ phenotype variance¡ variance of error¡ replication and mean trait¡ respectively. Data were analyzed using MSTATC software.
Results indicated that genotypes were significantly different for all traits. Ranges of days from germination to ear emergence and physiological maturity were 89-103 and 129-141 respectively. T he highest grain yield (4790 Kg.ha-1) and grain crop growth rate (14.1 g.m-2.day-1) was belonged to line No.29. The highest genetic variation coefficients were obtained from days from germination to ear emergence (43.6%) and biological yield (36.4%). Range of mean grain yield was 1898-4652 Kg/ha and lines No¡:5¡ 8¡ 15¡ 17¡ 20¡ 22¡ 23¡ 26 and 29 with grain yields 4494¡ 3748¡ 3820¡ 3777¡ 3757¡ 3717¡ 4007¡ 3780 and 4651 Kg.ha-1 respectively¡ were selected for advanced trails.
Regarding high similarity among grain yields with both grain growth rate (95%) and biological yield (86%) in cluster analysis and high genetic variation of the mentioned traits¡ the lines with both high biological yielding and grain growth rate were evaluated as the optimum genetic sources for breeding programs of triticale. Lines with both traits have capability to accumulate high amount of dry matter and to allocate a large proportion of this dry matter to grains.