Tolerance of peanut cultivars against drought stress at generative growth stage, leaf proline and total sugar content

English. The objectives of this experiments were to determine the effects of drought stress at generative growth stage on growth and yield of peanut, to evaluate the tolerance of six peanut cultivars against drought stress, leaf prolin and total sugar content. Peanut plants were grown in a plastic pot and subjected to stress condition during the period of 35-64 days (exp. I) or 35-80 days (exp. II) by watering them only every 4-7 days and were harvested at 75 days (exp. I) or at maturity in 100 days (exp. II). Peanuts were watered normally up to harvest period and used as control. Leaf prolin content were determined at 32, 47, and 64 days in exp. I and only at 64 days in exp. II. The results indicated that drought stress at generative growth stage reduced plant height, shoot dry-weight, and peanut yield. Sensitivity index calculated based on peanut yield variable indicated that the tested cultivars were classified into medium tolerance or sensitive against drought stress at generative stage. Leaf proline content increasing and absence of total leaf sugar content reduction could be used to indicate tolerance of peanut cultivars against drought stress at generative growth stage.

English. Penelitian bertujuan untuk menentukan pengaruh stress kekeringan pada fase pertumbuhan generatif terhadap pertumbuhan dan hasil kacang tanah, serta mengevaluasi toleransi, kandungan prolin dan gula total daun dari enam kultivar kacang tanah dalam kondisi stress tersebut. Kacang tanah ditumbuhkan dalam pot plastik dan diberi perlakuan stress kekeringan pada umur 35-64 hari sesudah tanam (percobaan I) atau 35-80 hari (percobaan II) dengan penyiraman setiap 4-7 hari sekali. Tanaman dipanen pada umur 75 hari (percobaan I) atau 100 hari (percobaan II). Tanaman yang disiram setiap hari dari saat tanam hingga panen digunakan sebagai kontrol. Kandungan prolin daun ditentukan pada umur 32, 47 dan 64 hari (percobaan I) dan juga pada 64 hari (Percobaan II). Hasil percobaan menunjukkan stress kekeringan yang diberikan menurunkan tinggi tanaman, bobot kering (BK) tajuk, dan hasil kacang tanah. Indeks sensitivitas yang dihitung berdasarkan peubah hasil menunjukkan kultivar yang diuji tergolong medium toleran atau peka terhadap stress pada fase pertumbuhan generatif. Peningkatan kandungan prolin daun dan kemampuan menjaga kandungan gula total daun agar tidak menurun kemungkinan dapat digunakan untuk menduga toleransi kultivar kacang tanah terhadap stress kekeringan pada fase pertumbuhan generatif.