Agronomic traits performance and stability of rice genotypes in highland ecosystem

Abstract

Rice is the most important staple food in the world. Development of rice cultivation area is needed to increase rice productivity through expanding of marginal land especially in high-elevation areas of Indonesia. Temperature, solar radiation and rainfall influence rice yield by directly affecting the physiological processes involved in grain production. The effects of abiotic stress on grain yield and yield components vary with growth stage, depending on variety and weather condition. The major constraint of rice cultivation in high elevation area is lack of cold tolerance varieties. The objectives of this research were to obtain the information of agronomic traits performance and stability of rice genotypes to be adapted in highland across three different high-elevations (700, 900 and 1200 m above sea level). The rice genotypes derived from mutation induction and hybridization treatment were cultivated in dry season (2011) and rainy season (2011/2012). Forty rice genotypes were used in dry season cultivation across two different high-elevations (700 and 1200 m above sea level). Twenty five rice genotypes were selected based on agronomic trait performance and grain yield in dry season and then cultivated in rainy season across three different high-elevations (700, 900 and 1200 m above sea level). Four stability analysis methods i.e. Finlay- Wilkinson, Eberhart – Russel, Francis - Kannenberg and AMMI were applied to analyze the stability of promising lowland rice lines. The results showed that the difference of high elevations had influenced on yield in dry season due to low air temperature (15ºC) during flowering period while there was no significantly effect in rainy seasons across three different high elevation areas. A minimum daily air temperature below 17°C in flowering period caused high unfilled grain numbers, low filled grain percentage, reduced grain weight, low panicle numbers, incomplete panicle extension, extended maturity date, extended grain filling period and low yield which varied among genotypes. Stability analysis indicated that some promising rice lines well adapted in different high altitudes areas. There were 12 rice lines stable based on Finlay Wilkinson method, Eberhart and Russell method (6 rice lines), Francis and Kannenberg method (16 rice lines) and AMMI models revealed three stable rice lines. The OS-30-199 mutant line produced the highest yield (4,69 ton/ha) among genotypes observed which highly significant over check variety, Sarinah (3,42 ton/ha).

Beras merupakan sumber makanan pokok bagi sebagian besar penduduk di dunia. Produksi beras perlu terus ditingkatkan untuk mengimbangi laju pertumbuhan penduduk. Upaya untuk meningkatkan produktivitas padi dapat dilakukan dengan perluasan areal tanam dengan memanfaatkan kawasan dataran tinggi. Faktor penghambat budidaya padi di dataran tinggi yaitu sebagian besar kultivar yang ditanam merupakan padi lokal yang memiliki karakter agronomi yang kurang menguntungkan, seperti berumur dalam, tanaman yang tinggi, dan produksi yang rendah. Berbagai faktor lingkungan turut mempengaruhi pertumbuhan dan hasil padi di kawasan dataran tinggi. Oleh karena itu, penelitian ini ditujukan untuk memperoleh informasi mengenai pengaruh ketinggian tempat terhadap keragaan karakter agronomi dan produktivitas genotipe padi serta mengetahui daya adaptasi dan stabilitas galur padi dataran tinggi.