Morphology, anatomy and nutrient content in pear buds

O cultivo da pereira surge no Sul do Brasil como uma alternativa consistente para a diversifica????o da fruticultura de clima temperado. No entanto, as varia????es de temperatura influenciam nos processos fisiol??gicos internos envolvidos na entrada e sa??da da endodorm??ncia que podem estar ligados ?? anatomia, fisiologia e metabolismo da planta. Portanto, esta pesquisa teve por objetivo avaliar as caracter??sticas morfoanat??micas e o poss??vel envolvimento dos n??veis de prote??na, carboidrato, c??lcio e ferro no abortamento de gemas florais de pereira, cultivar Nijisseik, no Sul do Brasil. Foram determinados os n??meros de prim??rdios, de duplas infloresc??ncias, comprimento, di??metro, volume, teor de carboidrato total, prote??na total, c??lcio e ferro das gemas. O n??mero de prim??rdios foi maior da segunda a quarta coleta e apresentou brusca redu????o da quarta para a quinta coleta. Da primeira para a segunda coleta houve significativa diminui????o do comprimento de gemas, ocorrendo leve aumento que se manteve nas demais coletas. O di??metro e o volume diminu??ram no decorrer das coletas. O teor de carboidratos totais teve varia????es durante os meses de coleta, apresentando redu????o durante o m??s de agosto com expressivo decr??scimo at?? setembro Um incremento significativo de prote??na foi observado de agosto a setembro, ??poca em que ocorreu eleva????o de temperatura e redu????o nas horas de frio. O teor de c??lcio foi reduzido no decorrer dos meses de junho a agosto, posteriormente aumentando at?? setembro. O ferro apresentou pequena redu????o do m??s de junho para julho, aumentando ap??s conforme o passar dos meses. Os resultados obtidos induzem a concluir que quanto maior o n??mero de prim??rdios, maior o n??mero de dupla infloresc??ncia e maior a intensidade de necrose. Este fato pode ser considerado como um dos primeiros fatores a desencadear o abortamento, seguido pela falta de nutrientes. O abortamento pode estar envolvido com a redu????o do teor de carboidratos totais, aliado a escassez de c??lcio e ao aumento do ferro no per??odo de dorm??ncia das gemas. As prote??nas totais provavelmente n??o tenham um efetivo envolvimento no abortamento de gemas. O abortamento de gemas n??o ?? causado apenas por um fator, mas sim por v??rios fatores que podem estar interligados, sendo necess??ria a continua????o de estudos abrangendo as poss??veis causas deste problema.The pear crop in southern Brazil emerges as a consistent alternative to the diversification of temperate fruit. However, temperature variations influence the physiological processes involved in internal input and output dormancy that may be connected to the anatomy, physiology and metabolism of the plant. Therefore, this study aimed to evaluate the characteristics and the possible involvement morphoanatomic levels of protein, carbohydrate, calcium and iron flower bud abortion in pear cultivar Nijisseik, in southern Brazil. It were determined the numbers of primordia, doubles inflorescences, length, diameter, volume, total carbohydrate content, total protein content, calcium and iron in gems. The number of primordia was higher in the second and the fourth harvest showing sharp reduction from fourth to fifth collection. The first to the second collection was significantly decreased length of gems, with a slight increase which was maintained in the other harvests. The diameter and volume decreased during the collections. The total carbohydrate had variations during the months of collection, a reduction during the month of august with a significant drop until september. A significant increase in protein concentration was determined from august to september, at this time there was an increase in temperature and reduction in hours of cold. The calcium content was reduced during the months from june to august and subsequent increase until september. Iron had a small reduction from june to july and after had increased as the months passed. According to the results, it can be concluded that the greater the number of origins, the greater the number of double inflorescence and the greater the intensity of necrosis. This fact can be considered as one of the first factors to trigger abortion, followed by lack of nutrients. Abortion may be involved with the reduction of total carbohydrate, and a shortage of calcium and also with increased iron in the period of dormancy of the buds. Perhaps the total proteins not have an effective involvement in bud abortion. The bud abortion is not caused by just one factor, but several factors may be interrelated, necessitating the continuation of studies covering the possible causes of this problem