Accession Number : AD0769143

Title :   Composition of Leaf Surface Waxes of 'Triticum' Species: Variation with Age and Tissue,


Personal Author(s) : Tulloch,Alexander P.

Report Date : 29 MAR 1973

Pagination or Media Count : 9

Abstract : The composition of cuticular wax from plants of spring wheat (varieties Selkirk and Manitou) and of durum wheat (variety Stewart 63) at various stages of growth, and of wax from different parts of the plants varies considerably. Wax was analysed, without preliminary separation, by GLC using Dexsil 300 as liquid phase. Alcohols are major components of wax from leaf blades and beta-diketones are major components of wax from leaf sheaths, especially the flag leaf sheath. Glaucousness of the leaf sheath is due to the high beta-diketone content. In the first 50 days after germination, before sheaths and flag leaf are completely developed, the major component is octacosanol (>50%). At 66 days, when sheath development is complete, beta-diketone content is greatest. Hydrocarbon composition differs for wax from leaf blade and leaf sheath and also for different leaf blades and between adaxial and abaxial sides of the flag leaf. From 66 to 100 days ester content of wax increases, especially in Selkirk wheat, apparently due to formation of wax containing high proportions of esters of trans-a, beta-unsaturated C22 and C24 acids. The content of these acids in the free fatty acids and of diesters based on these acids also increases during this period. (Author)

Descriptors :   (*Wheat, *Waxes), (*Plants(Botany), Waxes), Chemical compounds, Chemical analysis, Extraction, Aging(Physiology), Tissues(Biology)

Subject Categories : Biochemistry
      Organic Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE