Enhancing germination of kiwifruit seeds with temperature, medium and gibberellic acid

Abstract

Germination responses to temperature, medium and gibberellic acid (GA3) treatments were studied in kiwifruit (Actinidia deliciosa Chev. cv. Hayward) seeds. The seeds treated with four GA3 concentrations (0, 2,000, 4,000 and 6,000 ppm) were sown in trays with peat moss, perlite + heater humus and soil mixture and subjected to the temperatures of 20°C, 25°C, 30°C and 35°C with bottom heating, under controlled conditions. All the treatments significantly affected the kiwifruit seeds germination. Seeds sown in peat moss and subjected to the temperature of 35°C with bottom heating reached the maximum germination percentage (99.17%). Peat moss and 6,000 ppm GA3 treatment also had a high germination rate (79%). Moreover, peat moss caused an earlier start of germination than the other mediums and shortened the germination period. 1985;HASEY et al. 1994;VERMA et al. 1998;STRIK, CAHN 1996) also affect the germination and emergence of the kiwifruit seeds. As the kiwifruit cultivation has become an important trade in Turkey, growers needed to obtain more vines with seedling rootstocks suitable for water limited areas. The germination percentage of kiwifruit seeds was lower and there were unsatisfactory researches based on a single factor. Thus it was necessary to study a combined effect of several factors that would increase the germination of kiwifruit seeds.In the present study we tried to search out a combined effect of temperature provided by bottom heating, germination medium and gibberellic acid treatments on the germination of kiwifruit seeds under controlled conditions. MATERIAL AND METHODS Collecting the seedsKiwifruit seeds were obtained from soft, wellripened fruits of Hayward cultivar grown in the Black Sea Region. They were extracted by a low speed food blender, the liquefied pulp was washed away through a fine sieve with running tap water and then they were air-dried until they reached a 15% moisture content and were kept in 0.17 mmthick polyethylene bags in an open container at room temperature for the days prior to the beginning of the study. GA3 treatmentsSeeds were immersed in 2,000, 4,000 and 6,000 ppm GA3 (Berelex, Zeneca Ltd.) solutions for 24 h. The solutions have 7.3 pH at room temperature. The seeds for control application (0 ppm GA3) were immersed into distilled water with the same pH, temperature and time conditions. For each GA3 treatment, 1,800 seeds were soaked in twice their volume of solution. After GA3 application, seeds were washed with sterile distilled water, left to dry for 24 hours, and then dipped in a weak solution of bleaching powder for surface sterilization as indicated by SALE (1985). Germination mediumThe seeds were sown in the peat moss, perlite + heater humus and soil mixture in the 10 m long and 1 m wide trays with the set temperatures of 20°C, 25°C, 30°C and 35°C maintained by bottom heating. The peat moss (Klasmann-Deilmann Standard Form) had 75-80% water capacity, 15-20% water, 90-95% air capacity and 70-100 ppm dry density, and 6.0 pH. The perlite + heater humus...

Dormancy and germination responses of kiwifruit (Actinidia deliciosa) seeds to environmental cues

“…New, mature kiwifruit seeds did not germinate when placed in favourable conditions for germination at any of the tested temperatures. This result is consistent with the findings for the same species presented in previous reports (Lawes and Anderson, 1980; Chin et al ., 1992; Celik et al ., 2006). The failure of germination can be attributed to primary seed dormancy established during seed maturation on the mother plant (Hilhorst, 1995; Kucera et al ., 2005; Finch-Savage and Leubner-Metzger, 2006).…”

Growth of Different Olive Varieties Influences with Foliar Application of GA3 under Saline Conditions

“…Stratification under cool and moist condition or gibberellic acid treatment improves germination rates. Treatment with 2500ppm of gibberellic acid gives 31.67% germination [55]. The higher concentration of gibberellic acid of about 2000ppm to 6000ppm for 24 hours shortens the germination period.…”

Optimizing Seed Germination and Seedling Growth in Different Kiwifruit Genotypes

“…Although some studies showed that gibberellic acid can enhance kiwifruit seed germination [4,11,12], other studies indicated that cold moist stratification is more effective than gibberellic acid in breaking kiwifruit seed dormancy [8,9,13]. They also found that vermiculite is not a suitable medium for seed germination.…”

“…Therefore, for sustainable production and export, the kiwifruit industry needs to introduce novel kiwifruit cultivars with different flesh colors and flavors. To achieve this goal, a population of seed plants with natural or controlled crosses should be available [4]. The presence of dormant embryos in seeds and nonuniformity in seedling growth usually increase the losses of kiwifruit seed populations.…”

“…Because of the low germination ratio of Actinidia seeds, they must be treated with chemicals and kept in damp, aerated conditions, alternated between day and night, under low temperatures to increase their germination rate. According to researchers, stratification under cool and moist conditions and/or some chemical treatments can improve the germination rate of kiwifruit seeds [4,6,7].…”