This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Felker, F. C. Articles by Nelson, O. E. Search for Related Content PubMed PubMed Citation Articles by Felker, F. C. Articles by Nelson, O. E. Agricola Articles by Felker, F. C. Articles by Nelson, O. E.

Articles

Growth Characteristics, Grain Filling, and Assimilate Transport in a Shrunken Endosperm Mutant of Barley ¹

Department of Agronomy, University of Wisconsin, Madison, Wisconsin 53706, Department of Genetics, University of Wisconsin, Madison, Wisconsin 53706, United States Department of Agriculture, Agricultural Research Service, University of Wisconsin, Madison, Wisconsin 53706

The reported inheritance pattern of the seg1 shrunken endosperm mutant of barley (Hordeum vulgare L. cv Betzes) suggests that some defective process in the maternal plant tissues, and not in the endosperm, prevents normal grain filling in the mutant. To identify the physiological mechanism of the mutation, we compared growth, carbon exchange, and assimilate transport of Betzes and seg1 plants. Betzes and seg1 plants did not differ in mean relative growth rate, mean net assimilation rate, or carbon exchange rate. The rate and duration of grain growth of seg1 was lower than Betzes on intact plants and on detached, cultured spikes. Increasing the supply of sucrose in culture media up to 300 mM sucrose did not eliminate differences between normal and mutant grain growth. Translocation of ¹⁴C-labeled assimilates into seg1 grains ceased by 21 days after anthesis, and assimilates were diverted to lower plant parts. In contrast, assimilates were still entering Betzes grains at 29 days after anthesis. Evidence suggests that some maternal spike or grain tissue is affected by the mutation after the onset of grain filling. Identification of the specific seg1 defect may provide information about the cessation of normal grain filling.

This article has been cited by other articles:

				E. Grafahrend-Belau, F. Schreiber, D. Koschutzki, and B. H. Junker Flux Balance Analysis of Barley Seeds: A Computational Approach to Study Systemic Properties of Central Metabolism Plant Physiology, January 1, 2009; 149(1): 585 - 598. [Abstract] [Full Text] [PDF]