In two previous papers published in this journal, results concerning the impact of delayed harvest and late nitrogen top-dressing on certain quantity and quality characteristics of ripe grain were reported. The present paper gives an account of the process of grain formation in two Hungarian wheat varieties (MVM, Mv21), which were studied during the ripening period (from the 6th day after anthesis until full grain maturity). Eight sampels were harvested at different stages of maturity in four experimental years. To investigate the influence of nitrogen quantity on wheat proteins two different doses were applied. The changes in nitrogenous compounds giving a positive ninhydrin reaction in the stems, leaves and grains were also studied in the period after anthesis, as where the quantity and quality of different molecular weight proteins and amino acids. The ninhydrin positive substances decreased during the period of grain development in the stems, leaves and grains. This trend was observed mainly in the case of grains, due to gluten protein formation. The proteins were separated by HPLC. The migration of proteins between the plant tissues and in high molecular weight proteins the increase in the grain yield were monitored. The formation of free amino acids showed characteristic trends during the period of seed development. The changes in ornithine content observed during grain development could merit particular attention. There was a high ornithine concentration after flowering in both the wheat varieties studied. Later, a rapid decrease in the ornithin concentration could be detected, possibly due to the role of ornithine in amino acid biosynthesis through the absorption and transport of NH3.
|Number of pages||9|
|Publication status||Published - jún. 1996|
ASJC Scopus subject areas
- Agronomy and Crop Science