496 PB 178 AMMONIUM TOXICITY DURING PLUG SEEDLING GERMINATION AND PRODUCTION

Mapping Salinity Tolerance during Arabidopsis thaliana Germination and Seedling Growth

To characterize and dissect genetic variation for salinity tolerance, we assessed variation in salinity tolerance during germination and seedling growth for a worldwide sample of Arabidopsis thaliana accessions. By combining QTL mapping, association mapping and expression data, we identified genomic regions involved in salinity response. Among the worldwide sample, we found germination ability ...

Seedling Germination Stages

Seedling production of gurguéia nut (Dypterix lacunifera Ducke) I: Seed germination and suitable substrates for seedlings

Methods of seed germination and suitable substrates for seedling growth of gurguéia nut (Dipteryx lacunifera) were studied in the present work. The following methods of seed germination i.e. I and II) Room temperature water soak for 24 and 48 hours; III, IV, V and VI) hot water soak, for 5, 10, 15 and 20 minutes, respectively; and VII) mechanical scarification, were studied. The studied substra...

Structure and function of tomato leaf chloroplasts during ammonium toxicity.

Ammonium toxicity resulted in morphological modifications of tomato leaf chloroplasts. The chloroplasts, which are normally flattened around the protoplast periphery, became ellipsoidally rounded and dispersed through the protoplasm. The first apparent effect of plastid degradation was development of many vesicles from the fretwork. Later the grana lamellae swelled, and some disappeared. Eventu...

Pyrimidine degradation influences germination seedling growth and production of Arabidopsis seeds

PYD1 (dihydropyrimidine dehydogenase) initiates the degradation of pyrimidine nucleobases and is located in plastids. In this study, a physiological analysis of PYD1 employing T-DNA knockout mutants and overexpressors was carried out. PYD1 knockout mutants were restricted in degradation of exogenously provided uracil and accumulated high uracil levels in plant organs throughout development, esp...