Selection for Drought Avoidance in Sorghum Using Aerial Infrared Photography 1

摘要: In previous research, genetic variation in sorghum(Sorghum bicolor L. Moench) drought avoidance (maintenance of relatively high leaf water potential under c(,nditions soil moisture stress) was revealed. Practical screening for requires a fast field method. The response near infrared reflectance from plant leaves to status stimulated the development such method, based on photographic imagery water.stressed sorghum breeding nurseries. Aerial photography performed several altitudes over water-stressed and non-stressed nurseries at Lubbock, Halfway, Chillicothe, Texas. Noontime potentials, as measure avoidance, were determined selected strains each nursery. Total chlorophyll content respective Lubbock Chillicothe. Strain canopy color densities resulting transparencies analyzed by three methods: l) Scanning densitometry; 2) measurement integrated light transmittance manual photometry; 3) visual rating density. Over all locations, best correlations between density across obtained with photometric poorest scanning densitometry. For methods measurement, c.3rrelations Halfway. At this location, canopies dense, ground cover almost complete, film exposure optimal. Leaf chloroFhyll various not correlated density, although one strain presented consistent exception. method some guidelines its utilization are discussed.