Effects of pectinase, BAP and dry storage on dormancy breaking and emergence rate of Crataegus pseudoheterophylla Pojark.

Germination rates of Crataegus pseudoheterophylla are low and may be restricted by the presence of a hard endocarp and embryo dormancy. We examined the effects of pectinase [0, 0.5, 1, or 2 % (w/v)], benzylaminopurine (BAP) (0, 100, 200, 400, or 500 mg l(-1)) and dry storage (6, 9, or 12 months), on water uptake percentage (WUP) and seedling emergence rates with the endocarp intact or removed. Following treatments, seeds were subjected to a cold-warm-cold-warm-cold alternating temperature stratification regime, and then germinated at 23 A degrees C for up to 90 days. The highest germination percentage (GP) of 37.7 and 32.7 % were obtained in seeds without endocarp treated at 500 mg l(-1) BAP and dry-stored seeds for 12 months, respectively. WUP imbibed (96 h) in seeds with and without endocarp was 26.7 and 39.4 %, respectively, and the highest WUP was achieved in a period of 12 months (81 %). These results revealed that the application of BAP, pectinase, and dry storage significantly increased GP in C. pseudoheterophylla, probably mainly through dormancy-mediated processes. The results of the study confirmed that the seeds were semi-permeable by water.