Pollen Viability in Taro (Colocasia esculenta (L.) Schott) in Cuba.

In taro, pollen availability or variability, and the number of clones that produce inflorescences, are not worldwide problems today. However, in Cuba, the appearance of inflorescence is critical, since the high-yielding accessions are not the ones that produce the inflorescences; it rarely or never happens, but when it does, pollen is not viable in most cases. Therefore, the aim of this paper is to evaluate fertility and viability of pollen in taro accessions (Colocasia esculenta). The germplasm accessions of the species, preserved at the Center for Tropical Crops Research (INIVIT) were evaluated during the 2015-2016 period. Staining by aceto-carmine glycerol jelly or pollen viability test was performed to 19 accessions selected for their inflorescences in field conditions.  The result was expressed as the percentage with respect to the total number of pollen grains, using a descriptor of variations of pollen viability to determine if the accessions could be used as male parents in crop breeding programs. Five of the nineteen accessions evaluated were observed to produce viable pollen, which may be used as potential male and female progenitors in the genetic breeding program by species hybridation

Flowering of taro germplasm (Colocasia esculenta (L.) Schott) in Cuba

Research was done at the Center for Tropical Crop Research (INIVIT), to evaluate inflorescence of taro germplasm (104 accessions) in Cuba´s climatic conditions. Sampling was made every 7 days in the 2013-2014 period to evaluate inflorescence; accessions were characterized according to flowering parameters. The results showed that natural flowering by the 26-accession sample (25%), was observed to early blossom from July to October in 18 accessions (69.2%). Increased temperature and relative humidity lasted until November, when inflorescence ends

Viabilidad del polen en malanga (Colocasia esculenta (L.) Schott) en Cuba.

The utilization of improved clones introduced by the Institute of Tropical Crops. Research (INIVIT) has contributed to increased agriculture production and technology without additional costs. However, there are few taro clones in Cuban agriculture, mainly due to the ways for the multiplication of the species, which hinder the existence of broad sources of variability, both natural and induced. The aim of this paper was to evaluate pollen fertility in the accessions of this species of taro in a study made between December 2015 and December 2016. The acetocarmine gelatin glycerol staining or viability test was made to evaluate pollen fertility. Fully opened inflorescences with pollen were collected in order to determine if accessions could be used as male parent for crop breeding programs. The influence of some climatic factors like temperature, relative humidity, and precipitations during the crop cycle on the emission of inflorescence and pollen production, was evaluated. Five of all the accessions evaluated produced pollen, and three of the five had more than 50% pollen viability. Therefore, the 19 accessions of taro (C. esculenta) with inflorescence may be used as possible progenitors. The five accessions that produced pollen can be used as female and male progenitors.En el mundo hoy, no constituye un problema la cantidad de clones de malanga que emiten inflorescencias ni la disponibilidad del polen que producen ni la viabilidad del mismo, pero en Cuba la emisión de inflorescencia es de vital importancia, las accesiones con más rendimiento no son precisamente, las que emiten inflorescencias, lo hacen muy rara o ninguna vez y cuando lo hacen, casi nunca producen polen y pocas veces éste resulta viable. Por tal razón el objetivo de nuestra investigación es evaluar la fertilidad y viabilidad del polen en las accesiones de malanga (Colocasia esculenta). Se evaluaron las accesiones conservada en el germoplasma de esta especie conservada en el Instituto de Investigaciones de Viandas tropicales (INIVIT), en el período comprendido entre diciembre de 2015 a diciembre de 2016. Se seleccionaron 19 accesiones por emitir inflorescencia en condiciones de campo a las que se le realizó la Prueba de Tinción o viabilidad de polen de Gelatina de Acetocarmín Glicerol.  El resultado se expresó como el porcentaje respecto al número total de granos de polen, se empleó el descriptor basado en los rangos de viabilidad de polen para determinar si las accesiones pueden ser utilizadas como parentales masculinos en los programas de mejoramiento del cultivo y se determinó que cinco de las 19 accesiones evaluadas producen polen viable, las cuales permiten considerarlas como progenitores masculinos potenciales en el programa de mejoramiento genético por hibridación de esta especie

Pollen Viability in Taro (Colocasia esculenta (L.) Schott) in Cuba

In taro, pollen availability or variability, and the number of clones that produce inflorescences, are not worldwide problems today. However, in Cuba, the appearance of inflorescence is critical, since the high-yielding accessions are not the ones that produce the inflorescences; it rarely or never happens, but when it does, pollen is not viable in most cases. Therefore, the aim of this paper is to evaluate fertility and viability of pollen in taro accessions (Colocasia esculenta). The germplasm accessions of the species, preserved at the Center for Tropical Crops Research (INIVIT) were evaluated during the 2015-2016 period. Staining by aceto-carmine glycerol jelly or pollen viability test was performed to 19 accessions selected for their inflorescences in field conditions. The result was expressed as the percentage with respect to the total number of pollen grains, using a descriptor of variations of pollen viability to determine if the accessions could be used as male parents in crop breeding programs. Five of the nineteen accessions evaluated were observed to produce viable pollen, which may be used as potential male and female progenitors in the genetic breeding program by species hybridation

Floración del germoplasma de malanga isleña (Colocasia esculenta (L.) Schott) en Cuba

Con el objetivo de evaluar la emisión de inflorescencias en el germoplasma de malanga isleña (104 accesiones) en  las condiciones climáticas de Cuba, se desarrolló una investigación en el Instituto de Investigaciones de Viandas Tropicales (INIVIT). Durante los  años 2013-2014 se realizaron muestreos cada 7 días para evaluar emisión de inflorescencias, se caracterizaron las accesiones de acuerdo con  los descriptores relacionados con las inflorescencias. Los resultados apuntan a  la floración natural del  de 26 accesiones (25 %), de ellas  18 (69,2%)  florecen precozmente  en los meses de julio hasta octubre, en los que hay un incremento de temperatura y la humedad relativa período a partir del cual se reduce la emisión de inflorescencias hasta noviembre cuando culmina el proceso de floración.Flowering of Malanga isleña germplasm (Colocasia esculenta (L.) Schoot in Cuba  ABSTRACTIn order to evaluate the emission of inflorescences in the Malanga isleña  germplasm (104 accessions) in the climatic conditions of Cuba, an investigation was conducted in the Research Institute of Tropical Root and Tubers Crops (INIVIT). During the years 2013-2014, were sampled every 7 days to evaluate emission of inflorescences, accessions were characterized according to the descriptors related to the inflorescences. The results point to the natural flowering of 26 accessions (25%), of which 18 (69.2%) bloom early in the months of July to October, in which occurs an increase in temperature and relative humidity,  period from which the inflorescences emission is reduced until November when the flowering process ends

Caracterización morfoagronómica de clones de (Manihot esculenta Crantz) obtenidos por cultivo in vitro

Methods for cassava (Manihot esculenta Crantz) micropropagation have been refined in Cuba; however, few surveys have been carried out on characterization. A set of plants from ‘Señorita’, ‘CEMSA 74-725’ and ‘CMC-76’ clones was characterized. These plants were propagated by traditional methods (cuttings), organogenesis and starting from somatic embryos, so as, to study the genetic stability of the material through morphoagronomic descriptors taking into consideration in vitro culture techniques. 44 descriptors were evaluated and nine quantitative and eight qualitative variables were determined as the most important. Differences (between and within clones) were only detected for quantitative variables: width and length of leaf lobules, length of leaf stalk, total height and height of the first branch, stem number, number of marketable roots per plant, weight of commercial roots and stem thickness. These results obtained in this crop for the first time in Cuba are of great importance for a better knowledge of studied clones and constitute a base for further analysis to validate implemented in vitro culture methods.Key words: morphoagronomic descriptors, genetic stability, cassava, organogenesis, embryogenesisEn Cuba se han puesto a punto metodologías para la micropropagación de la yuca (Manihot esculenta Crantz), sin embargo poco se ha estudiado sobre la caracterización de los materiales vegetales obtenidos. En este trabajo se realizó la caracterización de un grupo de plantas procedentes de los clones: ‘Señorita’, ‘CEMSA 74-725’ y ‘CMC-76’, propagados por el método tradicional (estacas), por organogénesis y a partir de embriones somáticos con vistas a estudiar, mediante descriptores morfoagronómicos, la estabilidad genética de estos clones teniendo en cuenta las técnicas de cultivo in vitro empleadas. Se evaluaron 44 descriptores y se determinaron nueve variables cuantitativas y ocho cualitativas como las más importantes. Sólo se detectaron diferencias (entre y dentro de clones) para las variables cuantitativas: ancho y longitud del lóbulo de la hoja, longitud del pecíolo, altura total y de la primera ramificación, número de estacas y de raíces comerciales por planta, peso de las raíces comerciales y grosor del tallo. Estos resultados, que por primera vez se obtienen en Cuba en este cultivo, son de gran importancia para un mejor conocimiento de los clones en estudio y sirven como base para otros análisis futuros de validación de las metodologías de cultivo in vitro implementadas.Palabras clave: descriptores morfoagronómicos, embriogénesis, estabilidad genética, organogénesis, yuc