Rui Ribeiro dos Santos

Trigo duro: tolerância à toxicidade do alumínio em soluções nutritivas e no solo

Twenty three durum wheat inbred lines, one triticale and six bread wheat cultivars were studied in aerated nutrient solutions for aluminum tolerance with six different levels of aluminum (0, 1, 2, 3,4 and 6 mg/I), under constant temperature, 25 ± 1°C and pH 4.0. Aluminum tolerance was evaluated by measuring the root growth in an aluminum-free complete nutrient solution after a treatment of 48 hours in an aluminum solution. All duram wheat lines and Siete Cerros and Anahuac bread wheat cultivars were sensitive to 1 mg/l of Al3+. The bread wheat Alondra-S-46 was sensitive to 4 mg/l of A]3+ The triticale Chiva and the bread wheats BH-1146, IAC-24 and IAC-60 exhibited tolerance to 6 mg/l of Al3+. The same genotypes were also studied in trials carried out in the field using acid and limed soils. The durum wheat lines presented low grain yield (939-2,243 kg(ha) and the triticale and bread wheat cultivars, tolerant to Al toxicity, showed high grain yield (3,584-4,922 kg/ha) in acid soil. The best durum wheat line produced 4,128 kg/ha and the best triticale and bread wheat cultivars produced 4,547 and 4,906 kg/ha, respectively, in limed soil. These results confirmed that incorporation of aluminum tolerance into the durum wheat germplasm is needed in order to permit its growth in acid soils.

COMPORTAMENTO DE SEMENTES DE GRÃO-DE-BICO NA ARMAZENAGEM

Chickpea (Cicer arietinum L.) homogeneous seedlots, harvested in four sites in Sao Paulo State, Brazil, were initially evaluated for germination, vigor, moisture content and seed weigth. Thereafter, seedlots were submitted to storage, during two years, under the following conditions: (a) chamber at 12oC and 48% of relative humidity and (b) at room conditions. Germination and vigor tests (accelerated aging test, 42oC/48h), were applied at 6, 12, and 24 month intervals. All four seedlots showed similar water contents, ranging from 10.7 to 11.2%. However, seeds from Campinas were heavier than those harvested in the other localities. Seed germination and vigor decreased significantly with the increase of the storage period. Seedlots stored under controlled conditions presented higher germination and vigor values than those kept in the laboratory. Seeds harvested at Monte Alegre do Sul showed better germination and vigor than those from other places.