Analisis genetik dan seleksi generasi awal segregan gandum (Triticum aestivum L.) berdaya hasil tinggi

Abstract

The preliminary breeding research series to develop adaptive variety in wheat to low and medium land regions had been conducted. It was started from evaluation and identification of agronomical responses of some introduced varieties, selective hybridization and development the breeding populations, until selection in early generation to identify high yielding potential segregants. First field experiment was conducted at two Indonesian agroecosystems (BIOTROP as low land representative and Cipanas as high land representative) from Mei to September 2011 and others were conducted at Research Station of BALITHI, Cipanas. The first experiment results showed that location had significant effect on wheat performance. High temperature in low land decrease the sink-source capacity, accelerate the seed filling period, and increase the empty floret. The tested genotypes were classified into three tolerance level. Oasis was classified as tolerant genotype, HP1744, LAJ, Menemen, Alibey, Selayar, and Dewata were classified as medium tolerant, and Rabe, H-21, G-21, G-18, and Basribey classified as sensitive genotypes. Analysis of agronomical traits-controlling gene action showed that all of observed traits controlled by poligenic with additive and epistatic effects. The total tillering number, productive tillering number, shoot-root dried weight, seed weight/panicle, and seed number/pland had strong phenotypic correlation with seed weight/plant. On the other hand, based on path analysis only two traits which had high direct effect to seed weight/plant. Those traits are useful for secondary trait in improving yield potential. Four selected traits (seed weight/plants, productive tillering number, seed weight/panicle, ratio of empty floret) had been used to develop an selection index. Selected segregants in Oasis x HP1744 population are O/HP-F2-87, O/HP-F2-93, O/HP-F2-100, O/HP-F2-106, O/HP-F2-51, O/HP-F2-6, O/HP-F2-16, O/HP-F2-124, O/HP-F2-92, O/HP-F2-39, O/HP-F2-9, O/HP-F2-26, O/HP-F2-31, dan O/HP-F2-123. S/R-F2- 39, S/R-F2-13, S/R-F2-61, S/R-F2-19, S/R-F2-56, S/R-F2-7, and S/R-F2-64 are selected segregants in Selayar x Rabe population. In addition selected segregants in Dewata x Alibey population are D/A-F2-34, D/A-F2-13, D/A-F2-99, D/A-F2-22, D/A-F2-70, D/A-F2-4, D/A-F2-33, D/A-F2-80, D/A-F2-25, dan D/A-F2-65. All of the selected segregants have higher phenotypic performance in all observed traits than their parents.