Comparison of pollen production and quality characteristics of cultivated and wild almond species

There are several wild almond species in Turkey included Amygdalus orientalis (Mill.), Amygdalus turcomanica (Lincz.), Amygdalus fenzliana (Fritsch) Lipsky, Amygdalus trichamygdalus (Hand.-Mazz.) Woronow, Amygdalus arabica (Olivier), and Amygdalus webbii (Spach). These species offer a great value for the almond improvement; we studied the pollen viability, germination ratio and pollen yield for seven genotypes of A. orientalis, seven genotypes of A. turcomanica all growing under natural conditions in Southeastern Anatolia (Gaziantep and Şanlıurfa provinces, Turkey). Almond cultivars (Prunus dulcis [Mill.] D.A. Webb) obtained from Pozantı Agricultural Experimental Station, Çukurova University, were also used in the experiment. The pollen viabilities of various almond genotypes were determined by 2,3,5-triphenyltetrazolium chloride (TTC) and fluorescein diacetate (FDA) tests. At the end, pollen germination ratios were established according to Petri dishes method in vitro conditions (1% agar + 0, 10, 15 and 20% sucrose) while pollen yield was estimated with hemacytometric methods. The results indicated that pollen viability ratios were close to each other in both methods for the genotypes A. orientalis and A. turcomanica. Pollen germination ratios were found to be dependent on the sucrose content as well as on the genotypes used. The pollen of almond cultivars showed similar germination ratios in all of the sucrose concentrations while those pollens of A. orientalis and A. turcomanica genotypes displayed higher germination ratios in 10% sucrose. The number of anthers in one flower was higher in cultivars whereas the number of pollen grains was lower in other almond species. While the number of pollen grains in one flower was relatively high in A. orientalis genotypes, pollen quality was high in all the three species under research. The results suggested that these two species, namely A. orientalis and A. turcomanica could be employed for future almond breeding programs.