Grãos de pólen anômalos no clone CP76 de Anacardium occidentale L. (Anacardiaceae)

Abstract

-(Anomalous pollen grains in the clone CP76 of Anacardium occidentale L. (Anacardiaceae)). Anomalies of male gametophyte development was observed during anther development investigation in the clone CP76 of Anacardium occidentale. Androspores that stop development before the first pollen mitosis, and grains that show male gametophyte anomalies in early stage of development, was observed. The anomalous first mitosis generate two identical cells, or quite, or grains where cell plate was partially formed. Nuclear fusion occurs in those cells where partial cell walls were formed. The interruption of development before first pollen mitosis occurs in high frequency, on the other hand, the anomalies related with the first pollen mitosis are very rare.RESUMO -(Grãos de pólen anômalos no clone CP76 de Anacardium occidentale L. (Anacardiaceae)). Durante a investigação do desenvolvimento das anteras e grãos de pólen no clone CP76 de Anacardium occidentale foram observadas anomalias relacionadas ao desenvolvimento do gametófito masculino. Foram observados andrósporos que interromperam seu desenvolvimento momentos antes da primeira mitose, além de grãos que apresentaram anomalias relacionadas à fase inicial da gametogênese masculina. A primeira mitose anômala produziu grãos de pólen binucleados com células idênticas, ou quase, e ainda grãos onde a parede celular, oriunda da primeira mitose, foi incompletamente formada. Fusão nuclear foi observada nos grãos onde a parede celular foi incompletamente formada. A interrupção no desenvolvimento é muito freqüente, ao contrário das anomalias relacionadas à primeira mitose, de ocorrência muito rara.

Structural anomalies in pollen grains of Dyckia racinae L.B.Sm. (Bromeliaceae)

“…Other factors such as stress, caused by high temperatures and low water availability (Ji et al 2010; De Storme and Geelen 2013), or biotic factors such as hybridization (Chaturvedi et al 1990(Chaturvedi et al , 1999Bohra et al 2016), or cytomixis (Haroun 1995;Kumar and Srivastava 2009;Kumar et al 2010;Singhal and Kaur 2011) are also potentials causes for deviations and interruptions in pollen development that may not always lead to abortions. Deviant developmental pathways involve different punctual failures at the onset of, or during sporogenesis or gametogenesis (Ellison 1937;Sala et al 1989;Zucol 1998;Oliveira et al 2001;Kumar and Srivastava 2009) which can generate, in addition to abortions and viable pollen grains, a series of structural anomalies, such as incomplete walls, pollen fusions, numerous vegetative nuclei, among others cytological variations (Sunderland and Huang 1987;Kumar et al 2010).…”

“…Ten to 15 flowers were collected per individual at preand post-anthesis, in a total of 10 individuals. The flowers were fixed in a solution containing 1% glutaraldehyde and 4% formaldehyde in 0.1 M sodium phosphate buffer, pH 7.2 (McDowell and Trump 1976;Gabriel 1982), washed in the same buffer and in distilled water and dehydrated in ethyl alcohol series (O'Brien and McCully 1981). The material was pre-infiltrated in a 2-hydroxyethyl methacrylate (HEMA) and ethanol solution (1:1) during 12 h, followed by infiltration in HEMA for approximately 4 h until polymerization was completed (Gerrits and Smid 1983).…”