Vanessa Neumann Silva

Temperatura inicial de germinação no desempenho de plântulas e mudas de tomate

Seedling production is an important step for the tomato production and can be influenced by the initial temperature of germination. The aim of this study was to evaluate the effect of this factor in the tomato germination and seedling growth. It was used four seed lots which were tested for germination, accelerated aging and electrical conductivity to evaluate the physiological potential. After lots characterization, seeds were exposed to initial germination temperatures (20-30, 30, 33 and 35°C) and were analyzed by the SVIS® software. The seedling performance was evaluated using the emergence speed index and percentage, height and dry weight of shoots and roots. In general, the higher temperatures decreased the seedlings development. However, 28 days after sowing, the seedlings growth was similar among temperatures.

Image seedling analysis to evaluate tomato seed physiological potential

Computerized seedling image analysis are one of the most recently techniques to detect differences of vigor between seed lots. The aim of this study was verify the hability of computerized seedling image analysis by SVIS® to detect differences of vigor between tomato seed lots as information provided by traditionally vigor tests. Ten lots of tomato seeds, cultivar Santa Clara, were stored for 12 months in controlled environment at 20 ± 1 oC and 45-50% of relative humidity of the air. The moisture content of the seeds was monitored and the physiological potential tested at 0, 6 and 12 months after storage, with germination test, first count of germination, traditional accelerated ageing and with saturated salt solution, electrical conductivity, seedling emergence and with seed vigor imaging system (SVIS®). A completely randomized experimental design was used with four replications. The parameters obtained by the computerized seedling analysis (seedling length and indexes of vigor and seedling growth) with software SVIS® are efficient to detect differences between tomato seed lots of high and low vigor.

Internal morphology and germination of sunflower seeds 1

The use of high quality seeds is one of the important factors to increase productivity in areas cultivated with sunflower. The aim of this study was to investigate the relationship between internal morphology and germination of sunflower seeds with the X-ray test and computer-aided X-ray imaging analysis with the software Tomato Analyzer®, and check whether or not this relationship changes after a period of seed storage under different environmental conditions. For this purpose, five lots of sunflower seeds from cultivar Catissol 01 were used. They were evaluated during two experimental periods: at 0 and 4 months after storage; the first evaluation was performed to characterize the lots; after that, the seeds were stored in two environments, cold and dry chamber (10 °C and 30% relative air humidity) and non-controlled environment. The seed moisture content was determined and, after that, the seeds were submitted to the X-ray and germination tests. The X-ray analysis allowed the visualization of seed internal structure as well as the study between seed morphology and germination; the greater embryo size, in general, does not provide greater potential for seed germination; regardless of the storage conditions for the four-month period, there was no reduction in the area of the embryo.