Study On The Effect Of Different Temperature And Storage Form On Pollen Viability Of Sweet Cherry During The Period Of Pollen Storage

The European sweet cherries（Prunus auium L.）are mostly self-infertile varieties.Pollen viability is the basis for the high yield of pollination and insemination of fruit trees.It also plays an important role in the production of facility cherry.The amount and the viability of pollen is an important indicator of the pollen industrialized production.The research was conducted in the early April of 2017 and the middle and late March of 2018 at the Weihe Cherry Experimental Demonstration Station of Northwest Agriculture and Forestry University and the Mei County Cherry Experimental Station.The flower buds of seven sweet cherry cultivars as’Jimei’,’Sunburst’,’Van’,’Rainier,’Stella’,’Qinying 1’,and’13-33’were collected,and the organs of the flowers were observed.The water content of the pollen was measured by the oven-drying method.Sucrose suspension method and pectinase enzymatic method were used to detect the amount of pollen.The pollen viability,storage form and the temperature of pollen storage were studied by using TTC,I₂-KI staining and pollen in vitro culture methods.The research results can provide a theoretical basis for the hybrid breeding and production practice of sweet cherry.1.All of the flowers of the seven sweet cherry varieties as’Jimei’,’Sunburst’,’Van’,’Rainier’,’Stella’,’Qinying 1’,and’13-33’,have 5 petals,5 calyxes,1 pistil,and 30 to 38stamens.The number of single flower anthers of the varieties was uniform,and the deformity rates of’13-33’,’Stella’,and’Van flowers were higher,reaching 50%,46%,and 32%,respectively.2.The total moisture content of five sweet cherry varieties such as’Jimei’and’Sunburst’is between 39.65%and 68.62%.After drying in an oven at 25°C for 24 hours,the moisture content drops down to 4.98%to 6.1%.The pollen viability of all five sweet cherry varieties is over 40%.This drying method can be applied to pollen production.3.The result measured by using pectinase enzymatic hydrolysis method is better than that of the sucrose suspension method when testing the amount of single anther pollen,and the difference is significant.The yields of single anther pollen of 3 sweet cherry varieties as’Jimei’,’Sunburst’and’Van’are 2120,1952,and 2711 respectively.The amount of pollen produced from single flower was above 6×10⁴,and the highest amount is from’Van’which is 10.30×10⁴.As to’Jimei’and’Van’,the amount is higher than 5×10⁷,and in respect of’Sunburst’,the amount is more than 2×10⁷.As a result,the three sweet cherry varieties are suitable for the production of pollen varieties.4.When pollen treatments were measured,pollen in vitro culture method was more accurate and stable than the staining method,and the TTC staining method was better than I₂-KI staining.The I₂-KI staining method is not applicable to the determination of the pollen viability of each treatment.5.Pollen preserved in anther form exhibits better storage stability during long-term storage.Therefore,the pollen should be kept as complete as possible to maintain high pollen viability during the storage and sale of pollen.Low temperature can maintain pollen viability for a longer time.The sweet cherry pollen of’Jimei’,’Sunburst’,’Xianfeng’can maintain a more than 10%pollen viability at 4℃for 2.5 months;at-20℃low temperature and-80℃super low temperatre in the cryogenic storage,pollen viability can maintain active for a year,and the storage effect of the two temperatures showed little difference.The 365-day pollen viability could be maintained at more than 14%before storage,and that of’Xianfeng’could reach 36.22%stored below-80℃.In order to meet the needs of pollination in production,taking the actual production conditions into account,the temperature condition for pollen storage is best stored at-20℃.Among the three varieties of’Jimei’,’’’,’Van’,’Van’is the most suitable for pollen industrialized production because of its high pollen yields and excellent storage resistance.