Banca de DEFESA: KLEANE TARGINO OLIVEIRA PEREIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KLEANE TARGINO OLIVEIRA PEREIRA
DATE: 21/10/2022
TIME: 13:00
LOCAL: Videoconferência (Google Meet)
TITLE:

DISCONTINUOUS HYDRATION CYCLES WITH SALINE STRESS ELICITORS IN SEEDS OF CULTIVATED AND FOREST SPECIES

KEY WORDS:

Germination. Osmotic homeostasis. Water memory. Salinity.

PAGES: 94
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUMMARY:

Salt stress reduces water availability and affects early germination processes. Thus, seed hydration is the first process affected, followed by reduced seedling growth. In arid and semi-arid regions, water unavailability occurs naturally due to the environmental and climatic conditions that characterize these regions, but can be intensified by human actions. Discontinuous hydration cycles occur naturally in these regions. This has favored germination and promoted the acclimatization of native plant species that occur in the regions, such as Mimosa caesalpiniifolia and Pityrocarpa moniliformis, or for species cultivated under rainfed conditions, such as Zea mays and Vigna unguiculata. The strategic application of discontinuous hydration cycles in conjunction with abiotic stress elicitors in seeds can improve germination and seedling survival in conditions of low osmotic potential induced by saline stress. The objective of this study was to evaluate the effects of discontinuous hydration cycles with different salt stress elicitors in maize and cowpea seeds, as well as in the forest species M. caesalpiniifolia and P. moniliformis, through physiological evaluations (germination, vigor, initial growth and accumulation of biomass) and biochemical (organic solutes). In agricultural crops, the experiment was carried out in a completely randomized design following a 2 x 7 factorial arrangement, with four replications of 50 seeds. Corn seeds, cv. BR 206 and BRS 5037 Cruzeta, and cowpea seeds, var. Semper Verde and Pingo de Ouro were submitted to the following treatments: 0.0 mM NaCl; salt stress - 250 mM NaCl (corn) and 100 mM NaCl (cowpea); salt stress + three discontinuous cycles of seed hydration in water; salt stress + CHD with gibberellic acid; salt stress + CHD in hydrogen peroxide; salt stress + CHD in salicylic acid; and salt stress + CHD in ascorbic acid. For the forests, the experiment was carried out in a completely randomized design following the 2 x 12 factorial arrangement, with four replications of 30 seeds. The forest seeds were submitted to control and simulated saline treatments with 200 mM of NaCl. The other treatments were similar to those adopted for agricultural species, but applied in one and two cycles. Salt stress reduced germination, growth and biomass accumulation in seedlings of agricultural and forestry species. CHD benefited the germination, growth and biomass accumulation of seedlings of maize, cowpea and forest species under saline stress, mainly by inducing the synthesis of osmoprotectants. CHD in gibberellic and salicylic acids mitigated the effects of saline stress on maize and cowpea seedling formation that acclimated and resulted in higher germination potential, growth and biomass under saline stress of 250 and 100 mM NaCl, respectively. The best results for agricultural species were obtained after CHD with gibberellic acid and salicylic acid. For forest species, one cycle of priming in water and two of priming with gibberellic acid, promoted greater tolerance to the saline stress of 200 mM NaCl for P. moniliformis and M. caesalpiniifolia, respectively.

BANKING MEMBERS:
Presidente - 270.392.004-06 - SALVADOR BARROS TORRES - EMPARN
Externa ao Programa - 2835021 - CLARISSE PEREIRA BENEDITO
Externa ao Programa - 068.551.324-64 - EMANOELA PEREIRA DE PAIVA - UFERSA
Externa à Instituição - CHARLINE ZARATIN ALVES - UFMS
Externo à Instituição - GIVANILDO ZILDO DA SILVA - UFJ
Externo à Instituição - RÔMULO CARANTINO LUCENA MOREIRA - UFCG