The Tarim Basin,Xinjiang,China,a region important to the walnut industry,is affected by frequent heavy dust storms.Dust,including micro-particles(diameter<10μm),covers the surface of the walnut tree,thereby changi...The Tarim Basin,Xinjiang,China,a region important to the walnut industry,is affected by frequent heavy dust storms.Dust,including micro-particles(diameter<10μm),covers the surface of the walnut tree,thereby changing the surface-atmosphere interface microenvironment,which,in turn,influences the exterior and interior structure of the tree.Dust storms occur in spring and summer,during the flowering period of walnut,which is the key developmental stage leading to fruit formation.This study investigated the effects of dust on female flowers,male flowers,and the pollination of walnut.The morphological changes in the stigma during pollination were recorded.Stigma receptivity was studied via the benzidine–H2O2 method.Morphological features of the female floral organs and pollen were investigated using scanning electron microscopy.Pollen germination and pollen tube growth were examined by fluorescence microscopy.The results showed that dust had a significant inhibitory effect on male and female flowers,resulting in decreased catkin growth,reduced pollen viability(pollen viability was 20.13%),blocked pollen apertures,a reduced pollen germination rate on the stigma,and increased time needed for pollen tube appearance.Dust also had an inhibitory effect on stigma length and receptivity of female walnut flowers,with the length of the walnut stigma being reduced by 0.25~0.80 mm during the flowering process.In addition,there was decreased stigma mucus,resulting in stigma atrophy,decreased amount of pollen on the stigma,weakened stigma receptivity,and accelerated drying of female flowers.In the Tarim Basin,walnut flowering occurd at the same time as dust storms do,which had a negative impact on the floral organ,flowering and pollination of walnut.展开更多
文摘The Tarim Basin,Xinjiang,China,a region important to the walnut industry,is affected by frequent heavy dust storms.Dust,including micro-particles(diameter<10μm),covers the surface of the walnut tree,thereby changing the surface-atmosphere interface microenvironment,which,in turn,influences the exterior and interior structure of the tree.Dust storms occur in spring and summer,during the flowering period of walnut,which is the key developmental stage leading to fruit formation.This study investigated the effects of dust on female flowers,male flowers,and the pollination of walnut.The morphological changes in the stigma during pollination were recorded.Stigma receptivity was studied via the benzidine–H2O2 method.Morphological features of the female floral organs and pollen were investigated using scanning electron microscopy.Pollen germination and pollen tube growth were examined by fluorescence microscopy.The results showed that dust had a significant inhibitory effect on male and female flowers,resulting in decreased catkin growth,reduced pollen viability(pollen viability was 20.13%),blocked pollen apertures,a reduced pollen germination rate on the stigma,and increased time needed for pollen tube appearance.Dust also had an inhibitory effect on stigma length and receptivity of female walnut flowers,with the length of the walnut stigma being reduced by 0.25~0.80 mm during the flowering process.In addition,there was decreased stigma mucus,resulting in stigma atrophy,decreased amount of pollen on the stigma,weakened stigma receptivity,and accelerated drying of female flowers.In the Tarim Basin,walnut flowering occurd at the same time as dust storms do,which had a negative impact on the floral organ,flowering and pollination of walnut.
