Virus surveys of process vegetable crops pea beetroot and dwarf bean

In a survey of 14 processing crops and 7 pea seed crops throughout Canterbury Cucumber mosaic virus (CMV) was the most widespread with crop incidences of up to 20 Alfalfa mosaic virus (AMV) up to 11 Pea seedborne mosaic virus (PSbMV) up to 9 Soybean dwarf virus (SDV) up to 2 Turnip yellows virus (TuYV) up to 2 and Bean yellow mosaic virus (BYMV) up to 35 Red clover vein mosaic virus (RCVMV) was detected in peas for the first time in New Zealand with incidences of up to 35 Pea necrotic yellow dwarf virus (PNYDV) Faba bean necrotic yellows virus (FBNYV) and Broad bean stain virus (BBSV) were not detected In a survey of 8 beetroot crops TuYV was detected in Auckland at 1 incidence but not in Hawkes Bay Beet mosaic virus was detected at 1 incidence in both regions Fungal leaf spotting pathogens appear a greater concern in beetroot In 12 dwarf bean processing crops throughout Canterbury virus was only detected in early sown crops AMV and RCVMV were most widespread with incidences of up to 9; CMV with up to 7 incidence; then BYMV TuYV and SDV each with 1 incidence No Bean common mosaic virus was detected

Modelling phloem transport within a pruned dwarf bean: a 2-source-3-sink system

A mechanistic model of carbon partitioning, based on the Münch hypothesis of phloem transport and implemented with PIAF-Münch modelling platform (Lacointe and Minchin 2008), was tested for an architecture more complex than any tested previously. Using 11C to label photosynthate, responses in transport of photosynthate within a heavily pruned dwarf bean plant (Phaseolus vulgaris L.) to changes in source and sink activities were compared with model predictions. The observed treatment responses were successfully predicted. However, the observations could not be completely explained if the modelled stem contained only one phloem pathway: tracer from a labelled leaf was always detected in both shoot apex and root, whichever of the two leaves was labelled. This shows that bidirectional flow occurred within the stem, with solute moving simultaneously in both directions. Nevertheless, a model architecture with very little more complexity could incorporate such bidirectional flow. We concluded that the model could explain the observations, and that the PIAF-Münch model platform can be expected to describe partitioning in even more complex architectures.