Suitability of existing Musa morphological descriptors to characterize East African highland ‘matooke’ bananas

Article purchased; Published online: 18 Sept 2017Morphological traits are commonly used for characterizing plant genetic resources. Germplasm characterization should be based on distinctly identifiable, stable and heritable traits that are expressed consistently and are easy to distinguish by the human eye. Characterization and documentation of a representative sample of East African highland bananas (Lujugira–Mutika subgroup) was carried out following an internationally accepted standard protocol for bananas. Eleven cultivars were characterized using an existing set of minimum descriptors (31 qualitative and quantitative traits) with the aim of determining stable descriptors and the ability of these descriptors to distinguish among East African highland banana cultivars. There was variation in stability of these descriptors within cultivars and across the 11 cultivars. Only 10 (32%) out of 31 descriptors studied were stable in the 11 cultivars. However, they had similar scores and therefore are not suitable to distinguish between cultivars within this group. Nonetheless, these 10 descriptors may be useful for distinguishing the East African highland bananas as a group from other groups of bananas. A few descriptors were unique to the cultivar ‘Tereza’ and may be used to distinguish this cultivar from other ‘matooke’ cultivars. None of the quantitative descriptors were stable

Mammal responses to global changes in human activity vary by trophic group and landscape

Wildlife must adapt to human presence to survive in the Anthropocene, so it is critical to understand species responses to humans in different contexts. We used camera trapping as a lens to view mammal responses to changes in human activity during the COVID-19 pandemic. Across 163 species sampled in 102 projects around the world, changes in the amount and timing of animal activity varied widely. Under higher human activity, mammals were less active in undeveloped areas but unexpectedly more active in developed areas while exhibiting greater nocturnality. Carnivores were most sensitive, showing the strongest decreases in activity and greatest increases in nocturnality. Wildlife managers must consider how habituation and uneven sensitivity across species may cause fundamental differences in human–wildlife interactions along gradients of human influence.Peer reviewe

The burrowing nematode of banana: strategies for controlling the uncontrollable

The burrowing nematode of banana, Radopholus similis, is difficult, if not impossible, to control effectively. The lack of resistance in commercially acceptable cultivars and the perennial nature of the crop limit management options. Multiple-cycle treatment with systemic nematocides is presently the only effective tool available for reducing damage and sustaining yield. Most of these compounds are not toxic to the burrowing nematode, but only inhibit nematode activity for short periods of time. The repetitive application of non-fumigant nematocides has led to an increase in the rapidity of their biodegradation. From environmental, toxicological and consumer viewpoints, this type of pest management is unacceptable. Many attempts have been made to improve the situation with little or no impact to date. Many nematocides have been or are being removed from the market, and new replacement compounds have not been developed. Resistance has never been detected in commercial banana cultivars, and genetically modified cultivars are still unacceptable to a large number of banana consumers. Microbial-based strategies are considered to be a promising alternative approach to nematode management in banana. Progress can only be made if research and crop production systems are streamlined to support new management concepts. The following are discussed: 1) biological enhancement of planting material with fungal endophytes; 2) treatments with multiple nematode antagonists with diverse modes of action; 3) importance of induced systemic resistance in biological control systems; and 4) use of molecular tools to detect effective antagonists