AMINO ACID COMPOSITION OF MATURING ENDOSPERM FROM HEXAPLOID TRITICALE AND ITS SPRING RYE AND DURUM WHEAT PARENTS

The amino acid composition of the maturing endosperm of a triticale (X Triticosecale Wittmack) designated line 6A190 and its rye (Secale cereale L.) and durum wheat (Triticum durum Desf.) parents were determined. In all three cereals, rapid changes occurred during development in the free amino acid levels and in the nature of the endosperm proteins. The composition of the free amino acids of triticale more closely resembled the rye parent than the durum wheat parent throughout endosperm development. The amino acid composition of the proteins and peptides of triticale was intermediate to the rye and durum wheat parents at all stages of development. </jats:p

Evolution and Distribution of Hydrolytic Enzyme Activities during Preharvest Sprouting of Wheat (Triticum aestivum) in the Field

To date, research on preharvest sprouted (PHS) wheat has mostly been conducted on kernels germinated under laboratory conditions, which differ widely from conditions in the field. To obtain detailed knowledge of the evolution of hydrolytic enzyme activities in PHS wheat Triticum aestivum), a broad collection of samples from three varieties was obtained by harvesting before, at, and after maturity. Delaying harvest time coupled with periods of heavy rainfall caused sprouting in the kernels, observed as a drop in Falling Number and an increase in α-amylase activity. The appearance of α- and β-amylase, peptidase, and endoxylanase activity during field sprouting was independent from each other. Consequently, Falling Number could not be used to predict activity of other hydrolytic enzymes. When differentiating endogenous from kernel-associated microbial enzymes, results showed that α- and β-amylase and peptidase activity of PHS kernels were predominantly of endogenous origin, whereas endoxylanase activity was largely from microbial origin

EFFECT OF THE D GENOME ON THE PROTEIN OF THREE CULTIVARS OF HARD RED SPRING WHEAT

The protein compositions of the AABB tetraploid wheats derived from three common wheat (Triticum aestivum L. em Thell.) cultivars, Prelude, Rescue and Thatcher, were compared with those of their hexaploid counterparts. Quantitative distribution of the soluble protein fractions showed that all wheats contained similar quantities of albumins and globulins. Tetraploids of Rescue and Thatcher contained more gliadin, more glutenin and less insoluble residue protein than the corresponding hexaploids. In contrast, the tetraploid of Prelude contained similar amounts of gliadin, glutenin and insoluble protein residue as its hexaploid. Amino acid compositions of the flour and the solubility fractions for all wheats examined were essentially the same. Electrophoretic patterns of the proteins in the four soluble fractions showed that significant qualitative differences existed among the cultivars studied. The patterns for each extracted tetraploid and its hexaploid counterpart were essentially the same. </jats:p

Ion Beam Etching Op Soft Biological Tissue Maintained At Low Temperatobes

It has already been demonstrated (1) that it is possible to examine labile biological material kept at low temperatures using the temperature controlled stage module which has been developed for the Stereoscan scanning electron microscope. Following the success of these studies, attempts have been made to ion-beam etch soft biological tissue kept at liquid nitrogen temperatures inside the microscope column.Extremely hydrated plant material and delicate animal tissue were drained or damp dried, placed onto cooled aluminium stubs and rapidly quench frozen in Freon 22 (monochlorodifluoromethane) maintained at its melting point of -146°C by liquid nitrogen.</jats:p