Dinamika stomata pada padi varietas Hawara Bunar, IR64, Mutan, dan Transgenik saat cekaman kekeringan.

Abstract

Penggunaan varietas padi yang beradaptasi baik pada kondisi cekaman kekeringan sangat penting agar produksi padi tetap stabil. Penelitian ini bertujuan menganalisis dinamika stomata, laju transpriasi, dan komponen pertukaran gas pada empat genotipe tanaman padi pada kondisi cekaman kekeringan. Penelitian ini menggunakan rancangan acak lengkap dua faktor dengan lima ulangan. Faktor pertama adalah empat genotipe padi, sedangkan faktor kedua adalah dua taraf cekaman kekeringan. Tanaman padi berumur 73 hari setelah tanam (HST) diberi cekaman kekeringan selama 10 hari. Peubah yang diamati meliputi persentase stomata membuka dan menutup pada bagian atas dan bawah daun, laju transpirasi, konduktansi stomata, dan kandungan air di rongga stomata. Hasil penelitian menunjukkan persentase stomata membuka pada bagian atas daun berbeda nyata antar genotipe dan antar perlakuan cekaman kekeringan, sedangkan pembukaan stomata pada bagian bawah daun hanya dipengaruhi oleh perlakukan cekaman kekeringan. Persentase stomata membuka pada kondisi cekaman kekeringan pada varietas Hawara Bunar, IR64, mutan, dan transgenik berturut-turut 8,7, 3,0, 11,6, dan 36,1% lebih rendah dibandingkan persentase stomata membuka pada kondisi tanpa cekaman kekeringan. Semua genotipe padi hanya mengalami cekaman kekeringan sedang, sehingga perbedaan pembukaan stomata belum mampu menyebabkan perbedaan laju transpirasi, konduktansi stomata, dan kandungan air interselular antar pelakuan cekaman kekeringan.

The utilization of rice varieties that are well adapted to drought stress conditions is important to maintain rice production stability. The study aimed to analyze stomatal dynamics, transpiration rates, and gas exchange components of four rice genotypes under drought stress conditions. The study used two-factor completely randomized design with five replications. The first factor was four rice genotypes, while the second was two drought levels. Rice plants 73 days after planting (DAP) were drought-stressed for 10 days. Variables observed were percentage of stomatal opening and closing, transpiration rate, stomatal conductance, and water content in the stomatal cavity. The results showed the percentage of stomatal opening on the upper of leaves was significantly different among genotypes and between drought treatments, while stomatal opening on the underside of leaves was only affected by drought treatment. The percentage of stomatal opening under drought stress for Hawara Bunar, IR64, mutant, and transgenic were 8.7, 3.0, 11.6, and 36.1% respectively, which was lower than normal condition. The differences in stomatal opening did not cause the differences in transpiration rates, stomatal conductance, and intercellular water content between drought stress treatments, suggesting that all rice genotypes only experienced mild stress.