The presence of the root-knot nematode, Meloidogyne enterolobii, in guava commercial orchards in many Brazilian states has caused severe loss to growers. 146 guava and araçazeiro (wild guava) accessions were evaluated in a greenhouse and nursery in order to find resistant accessions to be used as rootstock for commercial guava cultivars. In the greenhouse, 15 to 20 cm tall plants were inoculated with 10,000 nematode eggs, in a randomized complete design with an unequal number of replications. Under field nursery conditions, after seed germination, the plants were transferred to plastic bags with nematode contaminated soil. Five months after inoculation, the greenhouse accessions were evaluated for nematode damage. The nematode reproduction factor (RF) was estimated and the accessions classified as resistant or susceptible. The plants grown in the field nursery were visually evaluated for the presence of root galls one year after transplanting to plastic bags. A total of 66 Psidium, including 14 araçazeiro and 52 guava accessions, were evaluated under field nursery conditions. Two araçazeiros were classified as resistant, and another segregated for nematode tolerance under nursery conditions. All the guava accessions were susceptible in both evaluation conditions. Among the 20 araçazeiro accessions evaluated in the greenhouse, three were resistant to the nematode (RF<1) and 9, collected in the state of Rio Grande do Sul, were immune (RF=0). After further investigation performed among some resistant araçazeiro accessions collected in southern Brazil, subtropical region, poor plant development was observed in the northeastern Brazilian semi-arid region and low grafting compatibility with commercial guava cultivars. The current strategy to overcome this guava pest includes developing interspecific Psidium hybrids among resistant araçazeiros and susceptible guava to obtain hybrids with adequate plant height and stem diameter, highly compatible when used as rootstock for commercial guava cultivars.

Diploon is a monospecific genus represented by Diploon cuspidatum, an arboreal species that has morphological characteristics distinct from those of other Sapotaceae species. In this study, Diploon cuspidatum leaves were characterized morphoanatomically in order to reveal additional diagnostic characters of their external morphology of the genus. The Diploon petiole presents shape and arrangement of the vascular system flat-convex, occasionally with one or two accessory bundles, many laticifers, and many prismatic crystals. The midrib is biconvex with a U-shaped cuticle on the abaxial side, and laticifers are associated with the vascular tissues. Mesophyll is dorsiventral, palisade parenchyma has two cell layers, T- and Y-shaped malpighiaceous trichomes are on the abaxial epidermis with a small stalk cell and long arm. The venation pattern is brochidodromous. Intersecondary veins run parallel to the secondary veins, and quaternary veins branch freely. Higher order veins are not present. Morphoanatomical analysis revealed important characteristics that reveal a set of structures common to Sapotaceae, in addition to characters that are important for the recognition and identification of D. cuspidatum.

Chrysophyllum is the second largest genus of Sapotaceae, with 81 species distributed in the neotropics. Little data are found in the literature regarding the morphology of seedlings and the early development of this genus. This study aims to morphologically characterize the fruit, seeds and seedlings of Chrysophyllum rufum Mart. Fruits were collected from individuals present in two fragments of the Atlantic Forest, Pernambuco. A sample of 100 seeds and 100 fruits was randomly selected to obtain the morphological data. The seeds were sown in plastic trays in a greenhouse. The fruits are bacoid, obovoid and globose with one or two functional seeds per fruit. The seeds are obovate, with the shape of the hilum ranging from elliptical transverse to oblong transverse. The embryo is cotyledonar, with a spatulated form. The cotyledons are foliaceous and whitish-translucent. The endosperm is abundant and whitish. Germination is epigeal, phanerocotylar and unipolar. The seedling has different characteristics than those of the adult individual, such as the shape and leaf consistency, type of leaf margin, type of venation variation, number of pairs of secondary veins, trichome coloring and abundance of latex. Keywords: morphological description, germination, propagules, Atlantic Rainforest. Caracterização morfológica do fruto, sementes e morfofunção de plântula do lacre-branco (Chrysophyllum rufum Matius -Sapotaceae).Resumo: Chrysophyllum é o segundo maior gênero de Sapotaceae, com 81 espécies distribuídas nos neotrópicos. Dados encontrados na literatura sobre a morfologia dos propágulos e desenvolvimento inicial do gênero ainda são escassos. O presente estudo tem como objetivo caracterizar morfologicamente o fruto, a semente e a plântula de Chrysophyllum rufum Mart.. Os frutos foram coletados de indivíduos presentes em fragmentos de floresta Atlântica, Pernambuco. Uma amostra de 100 frutos e 100 sementes foi selecionada aleatoriamente para obtenção dos dados morfológicos. As sementes foram semeadas em bandejas plásticas, em casa de vegetação. Os frutos são do tipo bacóide, obovóides a globosos, com uma ou duas sementes funcionais por fruto. As sementes são obovadas, hilo com forma variando de transversal elíptica a transversal oblonga. O embrião é cotiledonar, com forma espatulada. Os cotilédones são foliáceos, esbranquiçado-translúcido. O endosperma é abundante e esbranquiçado. A germinação é epígea, fanerocotiledonar e unipolar. A plântula apresenta caracteres diferentes do indivíduo adulto, tais como a forma e consistência foliar, tipo de margem foliar, variação do tipo de venação, número de pares de veias secundárias, coloração do tricoma e abundância do látex.

Chrysophyllum lancisepalum is here in described and illustrated as a new endemic species from the Atlantic forest in Brazil. Chrysophyllum lancisepalum is morphologically similar to C. januariense and C. sierpense, but distinguished by its chartaceous leaves, short petiole, attenuated leaf apex, rounded to obtuse leaf base, lanceolate sepals, fusiform fruit, and a seed with a basi-ventral seed scar. The new species is restricted to the states of Bahia and Espírito Santo, where it preferably grows in the Mussununga ecosystem, which is characterized by a coastal tableland geomorphology. Considering the vulnerability of C. lancisepalum and its very restricted occupation area, we suggest a preliminary conservation status in the Endangered (EN) category, according to the IUCN criteria.

Wissadula hernandioides (L’Hér.) Garcke is native to Brazil and can be identified by its subshrub habit, cordate and discolor leaves with usually stellate trichomes, yellowish flowers arranged in paniculate inflorescences, and schizocarpic fruits. Before our finding, this species was recorded in Brazil only in Cerrado, Atlantic Forest, Amazon and Pantanal vegetation. The population found in Caatinga domain and Pernambuco state expands the distribution of W. hernandioides. A morphological description, habitat, and the current geographic distribution, as well as original drawing are provided.