The seasonal changing of the chlorophyll content and stomata parameters in leaves of wild species of pear

In this experiment, we analyzed seasonal changing of chlorophyll concentration from July to late September with interval 20 days, and also stomata parameters leaves of wild species of pear. Leaves for investigation was collected from mid part of annual shoots with length 0.8-1.0 m. Preliminary work showed that chlorophyll content and stomata parameters in leaves are different during vegetation. So, the lowest chlorophyll showed P. korshinskyi. The highest measured in P. aromatica, P. nivalis, and P. pyrifolia. Almost the same pattern of the chlorophyll content was detected under calculating per fresh weight of leaf per cm 2 unit area. As in chlorophyll concentration between wild species stomata parameters were also characterized with ranging. The biggest area of stomata showed P. bretshneideri, P. ussuriensis, P. pyrifolia, P. aromatic, and the smallest P. betulifolia. However, it should be noted that morning time when the plant well saturated with water the wild species P. korshinskyi, P. aromatica, P. calleryana and P. bretshneideri showed the biggest stomata area. Subsequently, at 03 PM they start to reduction of stomata, whereas P. betulifolia and P. ussuriensis showed not significant ranging regardless of environment condition. The highest of density stomata per certain leaf unit (mm 2) and total area showed drought tolerance species- P. korshinskyi.