Diversidade genética e germinação de jenipapo

Abstract

Genipap (Genipa americana L.) is economically important species, and with great potential for intensive exploitation, however, lack information about the distribution of genetic diversity in the State of Sergipe, and there is little information about the behavior of seed germination under stress conditions. Thus, the aim of this study was to estimate the genetic diversity for pre-breeding individuals coming jenipapo the State of Sergipe, and evaluate the behavior of seeds subjected to different stress conditions. For evaluation of genetic diversity genomic DNA was extracted from young leaves of 76 adult subjects genipap following adaptation of CTAB protocol 2%, and was used in ISSR reactions that made total volume of 15 μL. 14 primers were tested seven selected due to the polymorphism detected in the amplified fragments gel under UV light. The profile of the amplified fragments was used to construct binary matrices, which were used to estimate genetic diversity. To the stresses by water restriction and salt, seeds were placed on germination paper soaked in the proportion of 2.5 times its weight in five osmotic potential (with polyethylene glycol PEG 6000 solutions at 0, -0. 1, -0. 2, -0. 3 and -0. 4 MPa); Salt stress and the seeds were subjected to solutions of sodium chloride at 0, 25, 50, 100 and 200 mol m-3. For thermal stress, seeds were germinated at 15, 25, 30, 35 and 40 °C. The seeds were also evaluated for water gain during the germination process and the data arranged in the imbibition curve. The variables analyzed were germination percentage (G %), germination speed index (IVG), the mean germination time (TMG), germination velodicade average (VMG), development (cm) and dry weight (PS) of seedlings. The genetic diversity of individuals genipap is distributed randomly, regardless of the region of their region of origin. And the less divergent individual´s were located in the municipality of Nossa Senhora do Socorro, which are not indicated for the study of pre-breeding. The seeds are affected when subjected to -0.3 MPa and -0.4 MPa. Biggest germination values were found in 25 mol m-3. The optimum temperature for seed germination is 30 °C jenipapo.