Health and transmission of fungi associated with seeds of Luehea divaricata

Abstract

Research related to the pathology of seeds of native forest species, açoita-cavalo (Luehea divaricata), is scarce. This study aimed to evaluate the sanitary and physiological quality of whipshorse seeds and the possible transmission of fungi associated with the seeds to the seedlings, in lots from Santa Maria - RS. Were 100 seeds used, divided into four repetitions of 25 per lot (2016 and 2018) and test. The health test was carried out in which the seeds without asepsis were placed in “gerbox” boxes with filter paper substrate at a temperature of 25 °C, with a photoperiod of 12 h for seven days. The germination test and the fungi transmission test seeds were conducted in a germination room at a temperature of 25 ºC, and a photoperiod of 12 h. Only the seeds used in the germination test underwent asepsis. The evaluations of the two tests consisted of the First Germination Count (at 14 days) and the count in the number of normal, abnormal seedlings, and non-germinated seeds (at 28 days). In the health test, fungi were identified and quantified: Fusarium sp., Alternaria sp., Aspergillus sp., Penicillium sp., Rhizopus sp., Cladosporium sp., Pestalotia sp. and Epicoccum sp. The Fusarium genus was identified associated with the symptoms of browning and rotting in seedling roots in the transmission test. The sample from 2018 showed greater vigor, reaching 21% at 14 days, not different from the lot of 2016 that reached 10%. The lot of 2018 presented the best results concerning health, vigor, and germination.