Poaceae Pollen Field Conditioning and Preservation Method

Abstract

Described are methods of field conditioning and preserving pollen and/or anthers from the Poaceae family of plants. A method of the present invention includes collecting fresh pollen and/or anthers and introducing the pollen and/or anthers to field conditioning conditions which regulate pollen moisture content. The field conditioning conditions may include an air flow at a humidity ranging from 50% to about 100% and a temperature ranging from about −10 to about 10° C. The field conditioning conditions and preservation conditions may further include a flow of one or more continuously refreshed, selected gases passing through pollen held on a permeable or impermeable surface. The field conditioning conditions may dehydrate the pollen to achieve a pollen moisture content of about 15% to about 35%. The preservation conditions may dehydrate the pollen to achieve a pollen moisture content of about 40% to about 58%.

1 . A method of preserving pollen from the Poaeceae family of plants comprising:
 (a) collecting fresh Poaeceae pollen; and   (b) subjecting said fresh pollen to field conditioning conditions for a period of time suitable to enhance pollen viability, including:
 (i) relative humidity ranging from about 50% to about 100%; 
 (ii) temperature ranging from about −10° C. to about 10° C.; and 
 (iii) air pressure ranging from about 15 kPa to about 150 kPa; 
 thereby to produce field conditioned pollen with enhanced pollen viability; and 
   (c) subjecting the field conditioned pollen to a preservation step.   
     
     
         2 . The method of  claim 1 , wherein the preservation step comprises preserving the field conditioned pollen in a controlled environment with a temperature ranging from about −10° C. to about 10° C.; and an adjustable air pressure; and further wherein the field conditioned pollen is dehydrated in the controlled environment to achieve a pollen moisture content of about 15% to about 35%, and the temperature and the relative humidity in the controlled environment are adjustable and maintain the pollen moisture content at about 15% to about 35%. 
     
     
         3 . The method of  claim 1 , wherein the pollen is from a cereal crop. 
     
     
         4 . The method of  claim 2 , wherein the controlled environment is a sealed container or a vented container. 
     
     
         5 . The method of  claim 2 , wherein the controlled environment is a room with a controlled atmosphere. 
     
     
         6 . The method of  claim 1  wherein the controlled environment includes a flow of one or more continuously refreshed, selected gases, wherein said gas displaces oxygen. 
     
     
         7 . The method of  claim 6  wherein the displacement of oxygen reduces metabolic activity of the pollen held in the controlled environment. 
     
     
         8 . The method of  claim 6  wherein the flow of one or more continuously refreshed, selected gases enters the controlled environment through an inlet and exits the controlled environment through an outlet. 
     
     
         9 . The method of  claim 8  wherein the inlet is positioned at the bottom of the controlled environment and the outlet is positioned at the top of the controlled environment. 
     
     
         10 . The method of  claim 6 , wherein the pollen in the controlled environment is held on an impermeable surface. 
     
     
         11 . The method of  claim 10 , wherein said impermeable surface is selected from the group consisting of a plastic surface, a metal surface, or a glass surface. 
     
     
         12 . The method of  claim 10 , wherein the flow of said one or more continuously refreshed, selected gases is a flow that passes through the pollen held on said impermeable surface. 
     
     
         13 . The method of  claim 6  wherein the pollen is held on a permeable surface. 
     
     
         14 . The method of  claim 13  wherein the permeable surface is a screen. 
     
     
         15 . The method of  claim 13  wherein the flow of said one or more continuously refreshed, selected gases is a flow that passes through the permeable surface and the pollen held thereupon. 
     
     
         16 . The method of  claim 6  wherein the selected gas is nitrogen gas and the concentration of the nitrogen gas in the controlled atmosphere is about 78% to about 100%. 
     
     
         17 . The method of  claim 6  wherein a continuous, adjustable, positive or negative air flow is provided such that air can be exchanged from the controlled environment at a rate of 1 or more times per hour. 
     
     
         18 . The method of  claim 6  wherein the flow of one or more continuously refreshed, selected gases includes at least one gas that serves as a drying agent. 
     
     
         19 . The method of  claim 18  wherein the moisture content of the gas that serves as a drying agent is below 1.0%. 
     
     
         20 . The method of  claim 6  wherein the temperature of the flow of one or more continuously refreshed, selected gases ranges from about −10° C. to about 10° C. 
     
     
         21 . The method of  claim 1 , wherein the fresh pollen is freshly collected from actively shedding plants. 
     
     
         22 . The method of  claim 1 , wherein the fresh pollen is collected from anthers by crushing, grinding, or otherwise disrupting the anther in order to obtain the pollen therefrom. 
     
     
         23 . The method of  claim 2 , wherein the dehydration of the pollen is conducted using one or more methods from the group consisting of:
 (a) heat drying;   (b) drying by means of a saturated salt solution;   (c) silica drying;   (d) sun drying;   (e) microwave drying;   (f) vacuum drying; and   (g) drying using a combination of controlled humidity and ventilation.   
     
     
         24 . The method of  claim 1 , wherein the relative humidity level is controlled by using:
 (a) a saturated salt solution;   (b) a two-pressure process;   (c) a two-temperature process; or   (d) one or more apparatus selected from the group consisting of:
 (i) a dew-point generator; 
 (ii) an atomizer; 
 (iii) a mixed-flow generator; and 
 (iv) a sonicator. 
   
     
     
         25 . A method of preserving pollen from the Poaeceae family of plants comprising:
 (a) collecting fresh Poaeceae pollen; and   (b) subjecting said fresh pollen to preservation conditions for a period of time suitable to enhance pollen viability, including:
 (i) relative humidity ranging from about 50% to about 100%; 
 (ii) temperature ranging from about −10° C. to about 10° C.; and 
 (iii) air pressure ranging from about 15 kPa to about 150 kPa; and 
   wherein the pollen is dehydrated to achieve a pollen moisture content of about 40% to about 58%, and the temperature, air pressure, and the relative humidity in the controlled environment are adjustable and maintain the pollen moisture content at about 40% to about 58%.