Dose of Paclobutrazol in the Growth of Sugarcane Seedlings in Vitro in the Acclimatization Stage

Abstract

Micropropagation has been widely used for the rapid multiplication of many plant species, where the final quality of the plant depends on the acclimatization stage. To obtain compact plants, with desired characteristics and adaptable to field conditions, the use of chemical inhibitors of growth is necessary. In sugarcane of the variety CP 72-2086 the effects caused by the growth regulator paclobutrazol (PBZ) in vitro plantas applied in the acclimatization phase are unknown. The objective of this research was to know the effect of paclobutrazol in the acclimatization phase in the growth and development of the vitroplantas of sugarcane of the variety CP 72-2086. The research was carried out in the greenhouse of the Faculty of Agronomy of the Autonomous University of Sinaloa, located at 24˚37'29"N and 107˚26'36"W, in Sinaloa, Mexico. Micro-propagated sugarcane seedlings were used by tissue culture; vitroplants were extracted from the flasks 24 hours before being transplanted into the greenhouse. The treatments of PBZ applied were the doses of 0 (control), 100, 150, 200, 250 and 300 mg∙L−1. The PBZ was applied when the seedlings had seven true leaves [(31 days after transplant (ddt)], and did not show gutting. At 36 ddt, the vitroplants of the trays were extracted and the variables evaluated were height (cm), stem diameter (mm), root length (cm), root volume (mL), root dry weight (g), aerial biomass dry weight (g), leaf area (cm2) and greenness in spad units. A randomized complete block design with three replicates was used. The results of the study indicated that the dose of 150 g∙L−1 of PBZ induced the growth of plants more compact and of better quality for the transplant.