Enhanced Production of Maize Pollen during Extreme Low Temperature for DH Wheat Development in Eastern Gangetic Plains of India

Wheat is one of the worlds most commonly consumed cereal grains. With the rapid increase in world population, the production of wheat will play a pivotal role in food security and the global economy. Conventional breeding programme for crop improvement involves hybridisation, selection and evaluation of plants which takes many generation cycles to reach homozygosity. Double haploid (DH) technology is a new boon for rapid development of new homozygous lines, which otherwise are achieved in more than seven years. Efficiency in pseudo-seeds production during wheat-maize hybridisation may lead to enhanced production of DH lines for varied purpose. Limitation of getting maize pollen during low temperature of winter in northern India is a challenge. Pollen of maize is shortly viable, and storage of the same at a lower temperature and high relative humidity could increase its viability up to 6 days at 4°C as proposed from earlier studies. Weather conditions greatly influence pollen shedding phenomenon. Cool, humid temperature delays the pollen shed while hot and dry conditions favor the same. Thus the present study was conducted to determine the efficiency of pollen development during extreme cold under four different conditions viz. open condition (under shade from top), in polyhouse, in the tunnel (inside polyhouse with hot air supply) and on the ground soil. The data were collected in terms of the health of the plants and pollen quantity. It was recorded that the plants in tunnel showed early spike emergence and pollen shedding in comparison to plants in a natural environment like in the open and on the ground. Chlorophyll content was least in plants in tunnel and highest in the plants sowed on the ground. Stem girth and plant height were also minimum in plants which were present in tunnel. In conclusion, for early availability and regular supply of pollen, the maize plants should be grown under a tunnel with hot air supply.