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Relationship Between Cotton Seedling Cold Tolerance and Physical and Chemical Properties

T.R. Speed, D.R. Krieg, G. Jividen


Increasing cotton's ability to germinate under cool night conditions would benefit the entire cotton industry. On the Texas High Plains, essentially every night during the planting period is below 16°C. Over half the night's have low temperatures below 10°C. These cool nights result in slow erratic emergence of weakened seedlings resulting in poor stands. The objective of our research was to determine if any physical or chemical properties of the seed were related to the seedling's ability to germinate and grow at temperatures less than 15°C. Six commercial varieties were grown at six locations across the High Plains. At harvest seed and lint were collected and physical and chemical properties assayed. Seed index, seed density, fiber properties, and total oil and fatty acid composition of the oil were determined. Regression analysis was used to correlate seed properties to germination ability. Seed density and fiber micronaire were both positively associated with germination capability at 15°C. The total oil was unrelated to germination; however, the relative concentrations of the saturated and unsaturated fatty acids in the oil were related to germination ability at 15°C. Our results indicated that the ability to germinate at 15°C was related to a low unsaturated to saturated ratio of fatty acids in the oil. This result is contrary to the literature on cold tolerance. However, we found that a high unsaturated fatty acid content was inversely related to seed density which was a measure of seed maturity which is highly correlated to cold tolerance. Research is continuing on the deposition of the fatty acids in the storage lipid fraction and the phospholipid fraction of the membranes and their relationship with cold tolerance of cotton seedlings during germination.

Reprinted from Proceedings of the 1996 Beltwide Cotton Conferences pp. 1170 - 1171
©National Cotton Council, Memphis TN

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Document last modified Sunday, Dec 6 1998