Raquel Silva Costa

Relação entre características morfológicas da cariopse e fusariose em milho

Relationship between caryopsis morphological characteristics and fusarium ear rot in corn Abstract _ Fusarium ear rot of corn caused by Fusarium moniliforme is responsible for severe yield losses. Probably fungal penetration in the caryopsis takes place at the silk scar and is related to the level of infection and the morphological characteristics of the caryopsis. The objective of this work was to identify morphological characteristics that confer resistance to the fungus in caryopsis of corn. Cary- opsis of six lines of corn, with and without inoculation with the pathogen, were evaluated using a stereomicroscope and scanning electron microscope. Morphological characteristics of the caryopsis such as tegument with saliences and reentrances accentuated, pericarp no much thick, starch less com- pact and presence of the silk canal favor the penetration of F. moniliforme.

Influência do momento de coleta sobre a viabilidade de grão de pólen em maracacujá - doce (Passiflora alata Curtis)

The aim of this work was to verify the best period to collect the pollen of Passiflora alata, with respect to its greater viability. Were collected 35 flower buds, 7 from each horary of collect (8h40, one day before anthesis, 8h40, 10h45 and 16h00 , in the day of anthesis and 8h40, one day after anthesis). The tests were made by coloring and in vitro germination. It was used the completely randomized design with 5 treatments and 7 repetitions and the averages were compared by Tukey´s test at 5% of probability. The test of viability by coloring ranged of 69,64 (in the day of the anthesis, 16h00) to 75,91 % (one day before anthesis, 8h40). The percentage of germination ranged from 49,18 (24 hours after anthesis) to 62,65 % (in the day of antese, 10h45). The best moment of collecting the pollen, with respect to the best viability and germination, is 10h45, in the day of anthesis.