ABSTRACT. The forage palm is widely cultivated in semiarid regions. It has a basic chromosome number of x = 11 and polyploids are the main variation. It is propagated via vegetative reproduction, and sexual propagation is rarely used. The objective was to associate the physiological quality of seeds of different cultivars of forage palm with the level of ploidy in the genera Opuntia and Nopalea. The cultivars used were: diploids (2n = 22) ‘F8’, ‘F21’, and ‘IPA Sertânia’; tetraploids (2n = 44) ‘Clone 6 African Elephant Ear’, ‘Mexican Elephant Ear’, and ‘V19’, and octaploids (2n = 88) ‘Round’, ‘Giant’, and ‘IPA Clone 20’. Thousand seed weight, length, diameter, number of seeds per fruit, first count and emergence percentage, shoot and root length, fresh and dry mass, electrical conductivity, and length, width, and fresh and dry weight of cladodes were measured. A nested scheme design was used, with three levels of ploidy and three cultivars within each level. The ploidy level positively influenced the number of seeds per fruit and the physiological quality of the seeds. Cultivars behave differently within the same ploidy level.

RESUMO A salinidade da água de irrigação interfere no crescimento de plantas de pinheira. Relatos indicam que o fósforo interfere no crescimento das plantas, com efeitos positivos na atenuação dos sais. Objetivou-se avaliar os efeitos da condutividade elétrica da água de irrigação (CEai) e doses de superfosfato triplo (SFT), no crescimento e teores foliares de mudas de pinheira (Annona squamosa L.). O experimento foi realizado em ambiente protegido, em delineamento experimental de blocos casualizados, com nove tratamentos, combinando-se doses de fósforo (0,00 g dm-3; 1,10 g dm-3; 3.00 g dm-3; 5,13 g dm-3; e 6.00 g dm-3 de SFT) e condutividade elétrica da água de irrigação (0,50 dS m-1; 1,10 dS m-1; 2,50 dS m-1; 3,91 dS m-1; e 4,50 dS m-1), no crescimento e teores foliares de Na+, K+, Ca+2 e P, em mudas de pinheira. As plantas apresentaram curva crescente de diâmetro caulinar com o aumento do SFT, porém, à medida que aumentou-se a CEai, houve efeito negativo para esta variável. O SFT influenciou positivamente na altura das plantas (2,02 g dm-2/14,50 cm), massa seca (1,25 g dm-2/0,90 g) e massa seca total (2,32 g dm-2/2,00 g). Com o aumento da CEai, houve incremento nos valores de Na+ (16,20 mg g-1), bem como na razão Na+/K+ (1,48 mg g-1), que ocasionam distúrbios metabólicos no meio celular. Doses de SFT melhoram o crescimento das mudas, não sendo fitotóxico; porém, aliados à CEai, reduzem o conteúdo de K+ em plantas de pinheira.

ABSTRACT The irrigation with saline water affects the growth of sugar-apple plants. Some reports indicate that phosphorus affects the plants growth, with positive effects on the salts attenuation. This study aimed to assess the effects of the irrigation water electrical conductivity (iwEC) levels and triple superphosphate (TSP) doses in the growth and leaf levels of sugar-apple seedlings (Annona squamosa L.). The experiment was conducted in a protected environment, in an experimental design of randomized block, with nine treatments that combined phosphorus doses (0.00 g dm-1, 1.10 g dm-1, 3.00 g dm-1, 5.13 g dm-1 and 6.00 g dm-1 of TSP) with irrigation water electrical conductivity (0.50 dS m-1, 1.10 dS m-1, 2.50 dS m-1, 3.91 dS m-1 and 4.50 dS m-1), to evaluate the growth and leaf levels of Na+, K+, Ca+2 and P of sugar-apple seedlings. The increased curve for stem diameter presented by plants was proportional to the amount of TSP. Nevertheless, the iwEC levels were inversely proportional to this variable. The use of TSP directly affected the plant height (2.02 g dm-2/14.50 cm), dry mass (1.25 g dm-2/0.90 g) and total dry mass (2.32 g dm-2/2.00 g). The increase in the iwEC levels was directly proportional to the Na+ values (16.20 mg g-1), as well as to the Na+/K+ ratio (1.48 mg g-1), which cause metabolic disorders in the cellular environment. The TSP doses improve the seedlings growth, proving to be not phytotoxic; however, in combination with the iwEC, they reduce the amount of K+ in sugar-apple seedlings.

RESUMO As cactáceas nativas ainda constituem um grupo de plantas que necessita de estudos sobre sua ocorrência, distribuição e dinâmica para subsidiar ações de manejo e conservação da família na região de inserção. O objetivo deste estudo foi analisar a estrutura e distribuição espacial de Cereus jamacaru DC. em uma mata de cipó (município de Campina Grande) e em uma caatinga arbórea (município de Monteiro) no semiárido da Paraíba, Brasil. Foram plotadas 100 parcelas com dimensões de 10 m x 10 m em cada área. Dentro das parcelas, todos os indivíduos foram etiquetados e mensurados na circunferência da base do caule com auxílio de uma fita métrica e a altura total com auxílio de tubos de PVC graduados. A estrutura espacial das populações foi obtida pela coleta da coordenada geográfica de cada indivíduo em cada área e expressa por meio de mapas de distribuição espacial. Foram amostrados 39 espécimes em Campina Grande, apresentando área basal (AB) de 0,69 m2, densidade absoluta (DA) de 39 ind. ha-1, frequência absoluta (FA) de 32% e tendência ao agrupamento (IGA=1,01). Em Monteiro, foram amostrados 38 indivíduos, AB = 0,47 m2, DA = 38 ind. ha-1, FA = 29% e tendência ao agrupamento (IGA=1,11). Os indivíduos de C. jamacaru apresentam padrão de distribuição agrupado em ambas as caatingas secundárias, sendo que a população de Monteiro enfrenta problemas de recrutamento, o que poderá implicar no insucesso reprodutivo da população futura. A espécie apresenta padrão de distribuição similar a outras cactáceas colunares.

ABSTRACT The native cacti still constitute a group of plants that require data in relation to its occurrence, distribution and dynamics with vegetation to subsidize management and conservation of families in the region. The aim of the study was to analyze the structure and the spatial distribution of Cereus jamacaru in a hypoxerophytic caatinga (In Campina Grande) and in a hyperxerophilic caatinga (In Monteiro) areas of semiarid of Paraíba state, Brazil. It had been plotted 200 parcels with 10mx10m in the municipalities of Campina Grande and Monteiro, PB state. In each parcel, all the individuals were sampled and labeled by measuring with the aid of tape measuring the base circumference of each specimen and height was earned with graduates PVC pipes. For evaluation of spatial structure, we obtained coordinates of each individuals, then, the maps of spatial distribution was produced. Thirty-nine 39 specimens were sampled in Campina Grande, showing basal area (BA) of 0.69 m2, absolute density (AD) of 39 ind. ha-1, the absolute frequency (AF) of 32% and a tendency to cluster (IGA = 1,01). In Monteiro, 38 individuals were sampled, AB = 0.47 m2, AD = 38 ind. ha-1, AF = 29% and a tendency to cluster (IGA = 1,11). The specimens of Cereus jamacaru showed clustering distribution pattern in the areas of secondary Caatinga, being that Monteiro's population faces recruitment problems. Thus, it could imply in reproductive unsuccessful population future. The species shows similar distribution pattern in relation to other columnar cacti.