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Drought resistance of crops is one of the great challenges for the world’s agricultural systems. Although the concept of ‘drought hardening’ has been known for many years, very little has been done on pre-harvest treatment that can help leafy vegetable crops resist drought stress on a retailer’s shelf. Our hypothesis was that for pot-grown vegetables a saline treatment could be found that would reduce transpiration pre- and post-harvest, but not harvestable yield. Coriander (Coriandrum sativum L.) was used as a model plant; several accessions (k-4, k-43, k-52, k-60 and k-62) from N.I. Vavilov Research Institute of Plant Industry, Russia and two commercial cultivars—Kashmir and Americanum—were studied. Plant growth, weight, transpiration, net CO2 assimilation, respiration, wilting, apparent petioles rigidity, leaf sodium content, elemental analysis and osmotic potential were assessed. We found that minor salinity (12.5 mM Na2SO4) triggered both drought and salt resistance mechanisms, which regulate appearance and shelf-life of pot-grown coriander. We found that the drought avoidance mechanisms (i.e. decreased transpiration and increased water use efficiency) and salt tolerance mechanisms induced by pre-harvest treatment could significantly postpone wilting and improve post-harvest habit of a leafy vegetable crop.

Coriander (Coriandrum sativum L.) was domesticated at some point of early history and now has no wild ancestors, so collections of accessions in genebanks are the only source of new genes for breeders. For growers of fresh herbs, coriander has proved to be the most problematic among popular herbs: it flowers early, flowering changes the taste of the rosette leaves and the leaves are also susceptible to sudden yellowing. In this paper we show that the use of vegetable genotypes from the subspecies microcarpum (Coriandrum sativum L. subsp. microcarpum DC.) can solve these problems. Accessions were obtained from the Genebank of the Vavilov Research Institute of Plant Industry, Russia. These vegetable genotypes showed a remarkable plasticity of physiological characteristics (time of flower initiation, time of whole-rosette senescence and heat resistance), which ensured a prolonged harvesting window. The vegetable genotypes also showed increase in biomass, number of leaves in the basal rosette and leaf area compared to fruit genotypes. Thus, vegetable genotypes from subsp. microcarpum proved to be an invaluable source of genes for breeders. Our study also extended knowledge on the morphogenesis and ontogenesis of coriander. First, we found that production of leaves in the basal rosette occurs at the same rate in winter and in summer, so does not dependent on season, but can be interrupted by elongation of the flowering stem, which is season-dependent. Second, we found that the time of whole-rosette senescence (yellowing) is an individual characteristic of a genotype, but is promoted by season similar to the flowering-time. Finally, we showed that the whole-rosette senescence (yellowing) occurs independently of the development of flowering stem.

Japanese knotweed is an aggressive alien species in Europe, North America, and Australia, causing a range of environmental problems. Eradication of Japanese knotweed is proving to be a difficult task, because the plant is able to propagate generatively by intra- and interspecific hybridization, and vegetatively from shoot and tiny rhizome pieces. Despite the economic consequences of Japanese knotweed on natural and built environments, its physiology is not yet fully understood; especially important are sink-source relations between old and young parts of the rhizome and growth of lateral and latent rhizome buds. Current methods of chemical control include three types of phloem-mobile herbicides, such as glyphosate, imazapyr, and synthetic auxins. These herbicides have limitations on their use, and all fail to eradicate the plant completely, for the reasons discussed in this review. Our aim is to suggest prospective approaches to enable chemical eradication: use of signals to induce controlled growth and development of quiescent rhizome buds; use of phytohormones, sugars, and light to increase allocation of phloem-mobile herbicides to the rhizome; use of xylem-mobile herbicides to exterminate the old rhizome parts; and use of different phloem-mobile herbicides at different growth stages.