Factors contributing to the development of aluminum resistance in the Madeiran maize germplasm

Abstract

Summary ± ZusammenfassungForty genotypes representing maize genetic diversity from the Island of Madeira were screened for resistance to aluminum (Al) in nutrient solution. Seeds of maize were obtained from local farmers from field plots spread around the island in a range of altitudes from 99 to 1000 m above sea level. The content of ionic aluminum and the pH of soils cultivated with maize were determined. The mean pH value of all examined soils was 4.9, while the mean ionic Al content was 0.76 cmol kg ±1 . Seventy-two hours (h) exposure to 100 and 200 lM Al followed by a 48 h recovery period of 4-day old seedlings revealed significant differences in Al resistance in the Madeiran maize germplasm. Root survival and regrowth exceeding 80 % of the seedlings were observed in 22 and 8 of the tested genotypes screened at 100 and 200 lM Al in nutrient solution. High Al resistance among Madeiran maize genotypes appeared not to be associated with the lower pH of soil, and did not correlate with the amount of soil Al 3+ or the altitude at the site of collection. The high level of Al resistance of the maize cultivars indicates an initial genetic trait enhanced by open pollination of maize. Zur Entstehung von Aluminiumresistenz von Maissorten aus Madeira beitragende Faktoren

Evaluation of the maize (Zea mays L.) diversity on the Archipelago of Madeira

“…The white and yellow maize that prevail on the Madeira Archipelago appeared to be well adapted to local environmental and edaphic conditions, which make their use more attractive for the local farmers then the commercial hybrids. Crop accessions were collected from farmer's plots, with some edapho-ecological parameters, ranging from 69 to 780 masl, altitude, 386 (Porto Santo) to 2,300 mm per year average precipitation, 4.23 to 6.87, soil pH (Pinheiro de Carvalho et al 2003, 2004a. Different rotational and manure application practices used by the farmers in different parts of the Archipelago may have also contributed to the diversification of maize.…”

“…Characterization of biochemical and agronomic traits of the Madeiran crop germplasm have also been conducted (De Freitas et al 2005;Pinheiro de Carvalho et al 2004a).…”

“…The agriculture is exercised by farmers, who often operate on small plots located on terraces ploughed on steep slopes of remote and isolated valleys ranging from the sea level up to about 1,000 masl. The Archipelago is of a volcanic origin, and shows specific soil and edaphic features, which have promoted adaptation of cultivars and evolution of local crop landraces (Pinheiro de Carvalho et al 2003, 2004a.…”

Morphological characterization of wheat genetic resources from the Island of Madeira, Portugal

“…1), average precipitation from 541 to 1314 mm per year, relative humidity between 70% and 85%, soil pH between 4.23 and 6.87, and soil organic matter between 0.55% and 4.40% (Pinheiro de Carvalho et al 2003, 2004a. The populations were morphologically analysed using quantitative and qualitative characters.…”

“…Madeira itself is the largest and highest of the islands, where Pico Ruivo (1861 m asl) and Pico de Areeiro (1820 m asl) are the highest peaks. The Archipelago is of volcanic origin, and shows specific soil and edaphic features, which have promoted the adaptation of wheat cultivars and evolution of local crop landraces (Pinheiro de Carvalho et al 2003, 2004a. Although the Archipelago of Madeira possesses a relatively mild subtropical climate, substantial differences in mean annual temperature and precipitation associated primarily with the elevation above sea level are recorded.…”