Growth and Photosynthetic Characteristics of Solanum tuberosum Plantlets Cultivated in Vitro in Different Conditions of Aeration, Sucrose Supply, and CO₂ Enrichment

Abstract

Growth characteristics, oxygen exchange, and carbohydrate and chlorophyll contents were determined 30 days after subculturing of single node-derived plantlets of Solanum tuberosum cv Haig cultivated in vitro. Cultivation conditions were: (a) photomixotrophy in closed vessel, (b) photomixotrophy in closed vessel on medium supplemented with silver thiosulfate, (c) photomixotrophy in aerated vessel, (d) photoautotrophy in air, (e) photoautotrophy in C02-enriched air. In photomixotrophic conditions, aeration of the vessel enhanced sucrose utilization and had a positive effect on plantlet growth. In photoautotrophic conditions, growth of the plantlets was slow in air and was strongly enhanced by CO2 enrichment of the atmosphere. Starch to sucrose ratios were higher in plants grown photoautotrophically than in plants grown with sucrose in the medium. Oxygen exchange characteristics on a chlorophyll basis were similar between the plantlets when measured under moderate light, and resembled those of greenhouse plant leaves. In high light, however, plantlets grown photoautotrophically in a C02-enriched atmosphere had higher oxygen exchange rates. We concluded from these results that potato plantlets in vitro in conditions (c), (d), and (e) developed C3-plant photosynthetic characteristics, which were in photoautotrophically grown plantlets comparable to those of field-grown plants.and could be a cause of growth abnormalities during the in vitro stage or during acclimatization.One can expect that achievement of photoautotrophic plant growth or aeration in photomixotrophic culture systems will improve in vitro cultivation efficiency, as well as plantlet behavior (8,14). Nevertheless, information is scarce on the effects of such culture conditions on plantlet physiology. We therefore investigated how culture conditions, i.e. different carbon sources (photomixotrophy and photoautotrophy at two CO2 levels) and confinement status (photomixotrophy with or without gas exchange with the atmosphere), could affect the growth, photosynthetic characteristics, and carbon metabolism of white potato (Solanum tuberosum) plantlets cultivated in vitro. MATERIALS AND METHODS Plant MaterialStock plantlets of Solanum tuberosum cv Haig were routinely subcultured from stem axillary buds on a medium containing Murashige and Skoog (18)

Effect of Photon Flux Density and Exogenous Sucrose on the Photosynthetic Performance during <i>In Vitro</i> Culture of <i>Castanea sativa</i>

“…Additionally, no assessed treatments produce more competent microshoots from the point of view of their similarity to plants grown in nursery conditions (seedlings). The results confirmed that using sucrose as external source of carbohydrates during proliferation stage of Castanea sativa microshoots had a positive effect on photosynthesis, chlorophyll content and growth, similar to that reported by Cournac et al [56]; Paul and Stitt [16]; and Ticha et al [17]. With this knowledge it is possible to establish strategies of mixotrophic culture that lead to production of competent microshoot during in vitro culture and, consequently, minimize the transfer stress and maximize the ex vitro survival rates.…”

“…So, when the sugar export from the leaf is reduced, it will be stored in these organs. An explanation for the inhibition of photosynthesis might be the low rate of regeneration of the carboxylation substrate RuBP due to the accumulation of soluble sugar in the leaves [56]. Our results indicate that in LL LS an increase in the starch granules was concomitant with lower net photosynthesis.…”

An optimal protocol for in vitro regeneration, efficient rooting and stable transplantation of chickpea

“…However, grafting is time consuming, requires special skills and the success rates vary significantly. Roots induced from cut ends of shoots of chickpea were shorter in length in semisolid medium as compared to liquid medium, similar to the earlier reports (Jackson et al, 1991;Cournac et al, 1991;Ebrahim and Ibrahim, 2000;Hazarika, 2006). The retardation in root length in the semisolid medium may be attributed to the relatively lower aeration in agar-gelled medium as indicated by earlier researchers (Hazarika, 2006;Pati et al, 2006;Rout et al, 2006).…”

The effect of sucrose on the development of hybrid walnut microcuttings (Juglans nigra x Juglans regia). Consequences on their survival during acclimatization

“…Assays of the soluble sugars (glucose, fructose and sucrose) were performed by the enzyme method described by Boehringer (1984 We observed that the hybrid walnut plantlets cultured on a medium with a high sucrose concentration had a high soluble carbohydrate content. It was similar to that observed in potato plantlets (Cournac et al, 1991) and in hop plants (Howard and Sykes, 1966). The high sucrose concentration also led to high dry matter accumulation in walnut plantlets but all plantlet parts were not affected similarly.…”