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Field pea (Pisum sativum), a major grain legume crop, is autogamous and adapted to temperate climates. The objectives of this study were to investigate effects of high temperature stress on stamen chemical composition, anther dehiscence, pollen viability, pollen interactions with pistil and ovules, and ovule growth and viability. Two cultivars ("CDC Golden" and "CDC Sage") were exposed to 24/18°C (day/night) continually or to 35/18°C for 4 or 7 days. Heat stress altered stamen chemical composition, with lipid composition of "CDC Sage" being more stable compared with "CDC Golden." Heat stress reduced pollen viability and the proportion of ovules that received a pollen tube. After 4 days at 35°C, pollen viability in flower buds decreased in "CDC Golden," but not in "CDC Sage." After 7 days, partial to full failure of anthers to dehisce resulted in subnormal pollen loads on stigmas. Although growth (ovule size) of fertilized ovules was stimulated by 35°C, heat stress tended to decrease ovule viability. Pollen appears susceptible to stress, but not many grains are needed for successful fertilization. Ovule fertilization and embryos are less susceptible to heat, but further research is warranted to link the exact degree of resilience to stress intensity.

Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.

"Watermelon (Citrullus lanatus) is one of the most important cucurbit crops in the world, with a total production of c. 118 million tons (FAO, 2017). It is a popular fruit in many Mediterranean countries and is widely cultivated. In Morocco an area of 16,680 ha is grown annually with a production of 619,322 tonnes in 2017. During 2015 watermelon plants with fruits showing cracking, yellowing and brown areas in the flesh were observed in some areas in Morocco. During 2017, similar symptoms were again observed in the regions of Marrakech, Tifelt and Zagoura. The symptoms observed (Fig. 1) were similar to those caused by Chickpea chlorotic dwarf virus (CpCDV, genus Mastrevirus, family Geminiviridae) which was recently reported affecting watermelon in Tunisia inducing ""hard fruit syndrome"" (Zaagueri et al., 2017a). Seventeen samples of watermelon leaves from symptomatic plants were collected (six from Marrakech, four from Tifelt and seven from Zagoura) and were subjected to total nucleic acid extraction by the TLES bufferbased method (50 mM Tris-HCl, pH 9, 150 mM LiCl, 5 mM EDTA, and 5% SDS), according to Noris et al. (1996). CpCDV infection was detected by dot-blot hybridization, using a digoxigenin-labeled probe targeting the coat protein gene (Zaagueri et al., 2017b) and was confirmed by PCR using a novel primer pair CpCDV-SEQ2 (5'-CGACACATAAGGTTCAGGTTG-3') and CpCDV-Tu-1145-R (5'-AGGCAACCCTTGGGAGTCA-3'), amplifying a 544 bp fragment in the Rep gene. Four samples out of fifteen collected in 2017 (samples 11, 12, 14 and 15) and one sample out of two collected in 2015 (Sample 'R') were positive for CpCDV by PCR (Fig. 2, upper panel). All five infected samples were collected in the Zagoura area, south-eastern Morocco. Infection in three of five of the samples was confirmed by dot-blotting (Fig. 2, lower panel). To further confirm CpCDV detection, three positive samples collected in 2017 were amplified by PCR using the CP-targeting primer pair CpCDV-CP-F/R (Zaagueri et al., 2017b) and the 501 bp products were sequenced on both strands. The three sequences (GenBank Accession Nos. MH500777 - MH500779) were almost identical except for four mismatches. BLAST analysis identified a CpCDV isolate from squash in Egypt (KF692356) as the best match in the NCBI database. These results constitute the first record of CpCDV infecting watermelon in Morocco and indicate that the virus has been present in the country since at least 2015. In the Mediterranean region, CpCDV has only been previously reported in Egypt (Fahmy et al., 2015) and Tunisia (Zaagueri et al., 2017b), and this report indicates that the virus may be more widely distributed than indicated by published records."

The mechanism of the biofungicide Prestop (Clonostachys rosea) was investigated for control of clubroot (Plasmodio-phora brassicae) on canola. The key product components were partitioned and assessed for their effect on pathogen rest-ing spores, root hair infection (RHI) and disease development using light microscopy, quantitative PCR and differentapplication treatments during infection. The whole product of Prestop was consistently more effective than the C. roseaconidial suspension or product filtrate alone in reducing RHI and clubroot development. This biofungicide showed littleeffect on germination or viability of resting spores. Two-application treatments at seeding and 7–14 days after seedingachieved greater clubroot control than a single application of the biofungicide at either seeding or post-seeding stage.This may indicate the need to maintain a high biofungicide dose in the soil during primary and secondary infection. Thisbiocontrol fungus colonized the rhizosphere and interior of canola roots extensively, and possibly induced plant resis-tance based on up-regulation of the genes that are involved in jasmonic acid (BnOPR2), ethylene (BnACO) and phenyl-propanoid (BnOPCL, BnCCR) biosynthetic pathways. It is concluded that the biofungicide Prestop suppressed clubrooton canola at least via root colonization and induced systemic resistance (ISR), and the latter may be through the modu-lation of phenylpropanoid and jasmonic acid/ethylene metabolic pathways elicited by the fungus.Keywords: biological control, Brassica napus, ISR, PR protein, SAR

This study used a versatile temperature-control device to assess the effect of temperature (12–40°C) and duration (2–12 weeks) of flooding on the survival of Leptosphaeria spp. in canola (Brassica napus) stubble. Canola basal stems with blackleg symptoms were submerged in water in small glass jars containing 20 cm3 soil on a thermogradient plate capable of simultaneously maintaining up to 96 independent temperature regimes. Flooded stems were sampled at 2-week intervals, surface-sterilized, and incubated on V8-juice agar for 10 days to recover the pathogen. Flooding for 2 weeks substantially reduced pathogen recovery relative to non-flooded controls and the pathogen was not recovered after 6 weeks of flooding, irrespective of temperature. The pathogen was eliminated slightly more rapidly at flooding temperatures >20°C than at 12–16°C. There was no difference between Leptosphaeria maculans and L. biglobosa in their ability to survive flooding. Stem tissues degraded most rapidly during the first 2 weeks of flooding, corresponding to a quick decline in pathogen survival during the same period. These results indicate that a paddy rice crop following winter rapeseed may minimize the impact of blackleg by eradicating the inoculum of Leptosphaeria spp. in stubble.

Clubroot caused by Plasmodiophora brassicae is an emerging threat to canola (Brassica napus) production in western Canada, and a serious disease on crucifer vegetable crops in eastern Canada. In this study, seven biological control agents and two fungicides were evaluated as soil drenches or seed treatments for control of clubroot. Under growth cabinet conditions, a soil-drench application of formulated biocontrol agents Bacillus subtilis and Gliocladium catenulatum reduced clubroot severity by more than 80% relative to pathogen-inoculated controls on a highly susceptible canola cultivar. This efficacy was similar to that of the fungicides fluazinam and cyazofamid. Under high disease pressure in greenhouse conditions, the biocontrol agents were less effective than the fungicides. Additionally, all of the treatments delivered as a seed coating were less effective than the soil drench. In field trials conducted in 2009, different treatments consisting of a commercial formulation of B. subtilis, G. catenulatum, fluazinam or cyazofamid were applied as an in-furrow drench at 500 L ha−1 water volume to one susceptible and one resistant cultivar at two sites seeded to canola in Alberta and one site of Chinese cabbage in Ontario. There was no substantial impact on the susceptible canola cultivar, but all of the treatments reduced clubroot on the susceptible cultivar of Chinese cabbage, lowering disease severity by 54–84%. There was a period of 4 weeks without rain after the canola was seeded, which likely contributed to the low treatment efficacy on canola. Under growth cabinet conditions, fluazinam and B. subtilis products became substantially less effective after 2 weeks in a dry soil, but cyazofamid retained its efficacy for at least 4 weeks.

This study investigated the influence of UV-B radiation (280‐320 nm) on survival of Candida oleophila strain O, an antagonist yeast that prevents postharvest diseases caused by Botrytis cinerea and Penicillium expansum on apple and pear fruits. Lethal doses (LD50 and LD90) were, respectively, 0AE89 and 1AE45 Kj m )2 for in vitro exposure and 3AE06 and 5AE 5K j m )2 for in vivo exposure. A screening test of UV-B protectants for strain O was also evaluated under in vitro and in vivo conditions. The in vitro results showed that sodium ascorbate (0AE1% and 0AE01%), riboflavin (0AE1%) and uric acid (0AE1% and 0AE01%) were the most effective and most suitable protectants. However, only riboflavin (0AE1%) and uric acid (0AE1%) were effective under in vivo conditions. The efficacy obtained with strain O against P. expansum, when subjected to UV-B radiation, was 75AE0% and 49AE2% for pathogen concentrations of 10 5 and 10 6 spores mL )1 , respectively. Adding riboflavin to strain O gave a similar efficacy (64AE2%). Applying strain O together with uric acid (0AE1%) was less active (47AE7%). Nonetheless, its efficacy when applied with the antioxidants sodium ascorbate (71AE1%) or ascorbic acid (82AE5%) was the greatest. Riboflavin and uric acid were the most cost-effective protectants, and could be included in thefinal formulation of strain O when applied preharvest.

Sugar beet (Beta vulgaris) is one of most important industrial crops in Morocco. In 2016, the cultivated area exceeded 61,000 ha and it's anticipated that this area will increase to 77,500 ha by 2020. However, sugarbeet yield is often…

In many Mediterranean countries, including Morocco, the environmental conditions are favourable for cucurbit crops and therefore such crops are of economic significance. In Morocco, the surface seeded with vegetable crops, which included…