Analisis rata-rata generasi jagung Unpad toleran naungan pada sistem agroforestri dengan albizia di Jawa Barat

Abstract

Aksi gen yang berperan terhadap suatu karakter dapat dipelajari dan dijadikan dasar dalam menentukan metode seleksi kegiatan pemuliaan. Analisa rata-rata generasi (generation mean analysis) merupakan salah satu cara yang dapat digunakan untuk menduga aksi gen, baik aditif, dominan dan interaksi non-alelik (epistasis) terhadap ekspresi suatu karakter. Metode ini digunakan untuk menduga model genetik yang berperan dalam ekspresi suatu karakter. Tujuan riset untuk menduga peran gen jagung toleran naungan pada sistem agroforestri dengan albizia. Penelitian dilaksanakan pada Oktober 2015 - Maret 2016 di Kebun Percobaan Kutamandiri, Kabupaten Sumedang. Materi genetik yang digunakan adalah galur toleran naungan M7DR 4.8.8, galur peka naungan G-203-1, F1 hasil persilangan G-2031 x M7DR 4.8.8, F2 keturunan dari F1, dan BC1F1 dan BC2F1. Hasil penelitian menunjukkan bahwa karakter jumlah baris per tongkol terdapat kesesuaian model dengan aditif-dominan dan tidak terdapat efek epistasis pada hasil persilangan antara G-2031 x M7DR 4.8.8. Model genetik m [d] [h] [i] sesuai dengan karakter tinggi tanaman dan bobot pipil per tongkol; model m [d] [h] [i] [l] sesuai dengan karakter panjang ruas, diameter tongkol, dan karakter bobot tongkol per tongkol; dan model m [d] [h] [j] [l] sesuai dengan karakter panjang tongkol. Karakter kadar klorofil tidak memiliki kesesuaian dengan model genetik yang diduga.ABSTRACTGene action that has a role in a character can be studied and used as a basic on determining the method of selection in breeding programs. Generation mean analysis is one of the methods that can be used to estimate the gene action, both additive, dominant and non-allelic (epistatic) interactions to the expression of a character. The method was used to predict the genetic model that plays a role in the expression of a character. The objective of the research was to predict the role of shade tolerant maize genes in the agroforestry system with albizia. The research was conducted on October 2015 - March 2016 at Kutamandiri Experiment Garden, Kabupaten Sumedang. The genetic materials was the shade tolerant line M7DR 4.8.8, shade susceptible G-203-1, F1 derived from G-2031 x M7DR 4.8.8, F2 breeds from F1, and BC1F1 and BC2F1. The results showed that number of row per cob character was suitable to the dominant additive model and there was no effect of epistasis on the crosses between G-2031 x M7DR 4.8.8. The genetic model m [d] [h] [i] corresponded to the plant height and the weight of seed per cob; model m [d] [h] [i] [l] corresponded to the character of the length of the node, cob diameter, and cob weight per ear; and the m [d] [h] [j] [l] model corresponded to the cob lenght character. The chlorophyll content character has no corresponding alleged genetic model.