Maturation indexes and physiological quality of seeds and fruits of Morinda citrifolia L.

Abstract

The seeds of Morinda citrifolia L. present unevenness and delay in germination in relation to other fruit trees. Knowledge about the physiological quality of seeds is extremely relevant for the production of seedlings and propagation of the species. Thus, the objective was to study maturation indices and the physiological quality of seeds and fruits of M. citrifolia. Seeds from freshly picked fruits, fruits harvested after seven days of maturation and freshly dropped fruits were used. The extracted and processed seeds were submitted to the following pre-germination treatments: GA3, KNO3 and H2O. The following were analyzed: fruit length and diameter, seed length, width and thickness, number of seeds per fruit, average number of seeds per kg, weight of 1000 seeds, germination, germination speed index, shoot and root length, seedling dry mass and percentage of normal seedlings. The experimental design used was completely randomized, with three stages of fruit maturation and six treatments, with four replications of 25 seeds. M. citrifolia seeds do not show tegumentary dormancy. The seeds of freshly harvested fruits and fruits harvested after seven days of maturation do not need pre-germination treatments. GA3 promotes greater germination in seeds of fruits harvested from the ground. Fruits that have just fallen to the ground have a higher content of soluble solids and a higher content of acidity. The storage of fruit in a refrigerator for a week provides the maintenance of texture characteristics, such as hardness, adhesiveness, elasticity and gumminess. Fruits with greater hardness have higher physiological seed quality.