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Anthocyanins, which give berryfruit their characteristic colour, have attracted the interest of researchers because of their putative health benefits. Over the past eight years, HortResearch has been analysing the anthocyanin content of numerous samples of different species of Vaccinium, Rubus and also Ribes nigrum. These samples were taken from different genotypes held in germplasm collections, cultivar and advanced selection trials, genetic studies and seedling populations. Averaged over all samples, Ribes had higher total anthocyanin contents (total ACY) than Vaccinium which was, in turn, higher than Rubus. However, all genera provided rich sources of anthocyanins and individual crop types within genera varied considerably. Five percent (i.e., 223) of our samples had total ACY of more than 5000 microg/g: most of these were blackcurrants, but some were black raspberries and three were ornamental blueberries. Vaccinium species generally contained the most diverse range of individual anthocyanins. In contrast, Ribes nigrum samples were dominated by cyanidin and delphinidin rutinosides which, on average, comprised almost 80% of the total ACY. For Rubus species almost all anthocyanins were cyanidins, although which ones were more prevalent varied with the species. The high degree of variation in total ACY and individual anthocyanin contents reported herein, coupled with the moderate to high heritabilities reported in the literature, indicate that good progress could be made in breeding cultivars with still higher total ACY levels.

Dynamics of pea seed infection by Pythium ultimum and Rhizoctonia solani: Effects of inoculum density and temperature on seed rot and pre-emergence damping-

Formulations of bacterial biocontrol agents were evaluated for the control of pea root‐rot caused primarily by Pythium ultimum and Rhizoctonia solani, at different levels of disease severity in field trials. Pseudomonas fluorescens (strain PRA25) in a peat‐based formulation increased yield by 17% over the untreated, in a trial with light disease infection, and by 120% in another with moderate infection. Other bacteria including P. cepacia (strain AMMD) and fluorescent pseudomonads increased seedling emergence, and decreased disease incidence and severity, but with variable effects on yield when disease level was light to moderate. Biocontrol agents resulted in only limited control when disease was severe. Control with Captan did not differ significantly from that obtained with bacterial biocontrol agents. The application of Rhizobium granular inoculum together with PRA25 granules did not differ from other treatments in disease control, indicating that Rhizobium is compatible with biocontrol agents. The population dynamics of a fluorescent pseudomonad introduced into the rhizosphere in peat or granular formulation was monitored using an antibiotic‐resistant mutant marker strain. The bacterium in peat formulation established a considerably higher population than that in granular formulation in 1993 trials, and a slightly higher population in 1994 trials. The higher population may have been responsible for the efficiency of root colonization and the effectiveness of disease control.