Download Cover, Ads and Contents
Chlorophyll Fluorescence in Developing ‘Top Mark’ Cantaloupe (Cucumis melo) Seeds as an Indicator of Quality
H.T. Wilson, Osamah Khan and G.E. Welbaum*
Seed maturity at harvest is one important factor that determines quality. Separating low-vigor developing seed from bulk-harvested lots is difficult because they often have the same physical characteristics as fully mature high-vigor seed. Non-destructive sorting based on chlorophyll fluorescence (CF) has the potential to remove low-vigor immature seed. This study examined whether CF may be used to identify and separate low-vigor, immature from high-vigor mature cantaloupe (Cucumis melo cv. Top Mark) seeds in the same lot.
Seed Production from Aeschynomene Genetic Resources Rescued and Regenerated Using Aeroponics
Jointvetch (Aeschynomene americana) and A. villosa are cover and forage crops. They require a long growing season and do not produce mature seed before the first hard freezes in Griffin, GA. Use of an aeroponic system was evaluated for rescuing and regenerating photoperiod and freeze-sensitive Aeschynomene accessions.
Response of 1-Aminocyclopropane-1-Carboxylate Oxidase Activity to Selenium in Dormant Stylosanthes humilis Seeds
Raimundo S. Barros, Frank James A. Pinheiro, Claudinéia R. Pelacani, Thamires F. Pereira and Dimas M. Ribeiro*
The enhancement of 1-aminocyclopropane-1-carboxylate oxidase (ACO) activity caused by soluble selenium (Se) compounds was observed in dormant seeds of Townsville stylo (Stylosanthes humilis) under in vitro (desalted extract) and in vivo (whole seed) conditions. Enzymatic activity was very low in dormant seeds, but was stimulated following an increase in 1-aminocyclopropane-1-carboxylic acid (ACC) content of Se-treated seeds.
Pomegranate Seed Germination and Dormancy Breaking Techniques
Mohammad Naser Taheri, Mahdiyeh Gholami*, Bahram Baninasab, Mostafa Mobli and Samad Moradi
Pomegranate (Punica granatum) propagation and seedling availability are fraught with difficulties. Dormancy and effectiveness of different seed treatments on germination performance and emergence of pomegranate seeds was investigated. Treatments included soaking seeds for 24 and 48 h at 25 °C in the dark in distilled water (hydropriming), 1 and 3% KNO3, and −0.4 and −0.8 MPa PEG (osmopriming), stratification in moist sand at 4 °C for 30 and 45 d, or scarification in 70% sulphuric acid for 10 and 20 min. A group of seeds was exposed to aril extracts during the germination period, instead of distilled water. Based on measured indices of germination performance and seedling quality, hydropriming for 24 h and KNO3 1% priming stimulated metabolism in pomegranate seeds. Stratification for 30 d resulted in seeds with the highest germination ability and best seedling quality, compared to other treatments. Both hydro- and KNO3-treated seeds performed better than control (untreated) seeds under drought stress, with a clear effectiveness of hydropriming in improving percentage germination at low water
potentials. When applied, aril extracts significantly inhibited germination. Hydropriming can be an effective method for promoting the propagation of the P. granatum fruit trees through mass production of seedlings, and would contribute to speeding up pomegranate breeding programs.
Adoption of Improved Local Wheat Seed Production Systems in Meskan and Sodo Districts of Ethiopia
Shimelis Araya* and Hussien Mohammed
Farmer-based improved seed production to satisfy smallholders’ demand for improved seed is an alternative and emerging approach in Ethiopia. This study determined decision variables that significantly constrained farmers’ adoption of improved local seed production systems in the Meskan and Sodo districts of the Gurage zone, Ethiopia.