GERMINATIVE CAPACITY AND ITS DECLINE RATE IN Lupinus bilineatus BENTH. SEED STORED FOR 15 YEARS

Abstract

The genus Lupinus has potential use in ecological restoration, agroforestry systems, and commercial forest plantations, due to its ability to fix nitrogen to the soil. The physical dormancy of its seeds allows their storage for long periods. Its longevity is partially known. The objective of this study was to analyze the weight, moisture content, germinative capacity, germinative energy, and viability of seeds of L. bilineatus Benth., after they had been stored for 15 years in a glass jar at room temperature (fresh, approximately 10-15 °C), and without light. A randomized complete block design was used for the experiment and the ANOVA was performed with a mixed procedure. The treatments were: control, mechanical scarification (sanding with sandpaper), and chemical (5, 10, 30, and 40-min immersion in sulfuric acid), with a day/night regime of 25/20 °C, and a 12-h photoperiod (fluorescent light). The results were compared with those obtained 15 years before. The following results were obtained: 66 766.2 seeds per kg, with a 6.60% humidity (fresh basis), 45% viability (tetrazolium salts test), and a 3.2 d germinative energy. There were significant differences among the treatments (p?0.0001). Scarification with sandpaper favored a greater germination (48.9%). The annual decline rate of the germinative capacity was 2.24%. Scarification can eliminate the physical dormancy of the seeds. Scanning microscopy showed that the seed coat has cuticle, macrosclereids, osteoesclereids, and parenchyma. The seed of L. bilineatus without coat contains 52.15, 9.21, and 2.83% raw protein, raw fat, and raw fiber, respectively.