Viability and longevity of pollen in Mexican lemon genotypes estimated by in vitro germination

Abstract

Studies of pollen viability and longevity in the genotypes selected as progenitors are useful to ensure the success of hybridizations in a breeding program. The present study was carried out in the Tecoman Experimental Field of INIFAP, in Tecoman Colima, Mexico, during the months of January and February of 2008 and 2009. The viability and longevity of the pollen were estimated in three varieties of Mexican lemon [Citrus aurantifolia): ‘Colimex’, ‘Colimon’ and ‘Lise’, two natural hybrids of Mexican lemon; CV 63-64 and CV 67-68 as well as the ‘Citrange C-35’ (C. sinensis x Poncirus trifoliata) as a control. The formulations of Brewbaker and Kwack (1963); Lora et al. (2006); Leal (1969) modified were evaluated. The three culture media promoted in vitro germination of pollen grains in very similar proportions, close to 20%. The genotypes, ‘Colimon’ and ‘Lise’ registered low germination percentages of 0.78% and 3.05% respectively. On the other hand, the variety ‘Colimex’ and the natural hybrid CV 63-64, had intermediate percentage values, while the ‘Citrange C-35’ and the natural hybrid CV 67-68 reached the highest pollen viability percentages (43.3% and 39.69% respectively) and can function as pollen donors. The pollen of all genotypes evaluated, conserved at room temperature, which fluctuated between 21 °C and 30 °C, lost almost 100% of its viability 48 h after anthesis. This is the first study on the viability and longevity of Mexican lemon pollen using in vitro germination tests.