Effect Of Different Sources Of Molybdenum On Photosynthesis And Pollen Development Of Oilrape And Winter Wheat

Molybdenum is an essential trace element for crops.China is lacking of molybdenum cultivated land about 44.67 million hectares,accounting for 46.8% of the total cultivated land area.In recent years,the application of molybdenum-containing nanomaterials in agriculture has received extensive attention.In this paper,common potassium molybdate and ammonium molybdate are used as comparative materials to study the effects of nano-potassium molybdate on photosynthesis and pollen development in winter wheat and oilrape.The main results obtained are as follows:1.Foliar nano-potassium molybdate and common molybdenum fertilizer can increase the molybdenum content of winter wheat and oilrape,but foliar nano-potassium molybdate has better treatment effect.Compared with the control without foliar molybdenum fertilizer,the content of molybdenum in leaves,spikes,and seeds of winter wheat treated with foliar nano-potassium molybdate significantly increased by 637%,180 and 135%,and the accumulation of molybdenum increased by 877%,239%,and 248% while foliar common potassium molybdate treatment increased the molybdenum content in winter wheat leaves,spikes and seeds by 488%,137%,and 120%,and the accumulation of molybdenum increased by 656%,151%,and 186%;compared with the control,foliar nano-potassium molybdate treatment increased the molybdenum content of oilrape stems,glumes,and seeds by 114%,94%,and 210%,respectively,and the accumulation of molybdenum increased by 130%,118%,and 305%,respectively,while foliar common potassium molybdate treated oilrape stems,glumes and seeds increased by 94%,74%,and 153%,respectively,and the accumulation of molybdenum increased by 102%,97%,and 223%,respectively.In general,the increase in molybdenum content and accumulation of molybdenum after foliar molybdenum fertilizer in winter wheat is higher than that in oilrape.2.Foliar nano-potassium molybdate and common molybdenum fertilizer can increase the yield of winter wheat and oilrape,but foliar nano-potassium molybdate treatment increases the yield even more.Compared with the control without foliar molybdenum fertilizer,the yield of winter wheat treated with nano-potassium molybdate increased by 46%,while the yield of foliar common potassium molybdate and ammonium molybdate increased by 28% and 24%,respectively;compared with the control,the yield of oilrape treated with foliar nano-potassium molybdate increased by 30%,while the yield of foliar common potassium molybdate and ammonium molybdate increased by 27% and 29%,respectively.These results also indicate that the yield of winter wheat coated with nano-potassium molybdate in molybdenum-deficient soil is higher than that of oilrape.3.Foliar nano-potassium molybdate and common molybdenum fertilizer can affect the photosynthetic pigment content and gas exchange parameters of winter wheat and oilrape,but foliar nano-potassium molybdate has a greater effect on winter wheat.Compared with the control without foliar molybdenum fertilizer,the content of chlorophyll a,chlorophyll b,total chlorophyll,and carotenoids,and net photosynthetic rate of winter wheat leaves treated with foliar nano-potassium molybdate increased by 142%,98%,126%,116%,and 38%,respectively.In comparison,foliar common potassium molybdate treatment only significantly increased the chlorophyll a and total chlorophyll of winter wheat leaves by 91% and 83%,while chlorophyll b,carotenoids content,and net photosynthetic rate were not significantly different;compared with the control,foliar nano-potassium molybdate treatment of oilrape,chlorophyll b,total chlorophyll,and carotenoids content increased by 26%,22%,and 19%,while the photosynthetic pigment content of foliar common potassium molybdate treatment did not show significant differences.4.Foliar nano-potassium molybdate affects the pollen development of oilrape.The outer wall of oilrape anther sacs treated with foliar nano-potassium molybdate had a complete shape.There were four pollen sacs in the anther sacs with abundant pollen grains,while the outer wall of the pollen sacs with without molybdenum was incomplete and the pollen grains in the pollen sacs were few;the shape of pollen grains treated with nano-potassium molybdate was round and uniform in size.Partial pollen grains were broken without the control treatment of foliar molybdenum fertilizer;compared with the control,the vigor of oilrape pollen treated with nano-potassium molybdate treatment increased by 169%.Foliar common potassium molybdate and ammonium molybdate increased pollen viability by 11% and 31%,respectively.