Effects of Potassium Deficiency and Excess upon Certain Carbohydrate and Nitrogenous Constituents in Guayule.

The nature of the carbohydrates of translocation and the reserve carbohydrates in guayule has only recently been elucidated. McRARY and TRAUB (28) isolated a fructosan, tentatively identified as inulin, and HASSID et al. (19) definitely characterized this substance as inulin. Later, TRAUB and SLATTERY (41) showed that in addition to inulin, levulins are also present in guayule tissue, and in relatively greater amounts. TRAUB aid SLATTERY (41) also indicated the importance of relating the 89 per cent. ethanol soluble and insoluble levulins to planit functioning. TRAUB, SLATTERY and WALTER (42) have shown that the carbohydrates of translocation in guayule are apparently the free reducing sugars since they are always present in relatively small amounts in the roots, stems alnd branches but predominate in the leaves. These workers have also shown that of the total free reducing sugars, the amounts of free nion-fructose sugars are always greater than the amounits of free fructose in spite of the fact that the chief reserve carbohydrates in guayule are polymers of fructose, levulins and inulin. The coniditions of the present experiment were not conducive to large accumulations of inulin, or higher polymer levulins, insofar as the experiment consisted of a phase of rapid growth. So far as the writers are aware, no detailed study has been made of the nitrogenous fractions in guayule. Effects of potassium supply upon growth responses and mineral contents of guayule plants and upon cation and inorganic and organic aniion contents of the leaves have been reported (8, 9). In this paper are considered carbohydrate and nitrogenous fractions in tissues of the same plants. Carbohydrate fractionis in plants grown with and without potassium are also reported.