Dynamics of extractable carbohydrates in Pisum sativum. I. Carbohydrate and nitrogen content in pea plants and cuttings grown at two different irradiances

Abstract

1982. Dynamics of extractable carbohydrates in Pisum sativum. I. Carbohydrate and nitrogen content in pea plants and cuttings grown at two different irradiances. -Physiol. Plant. 55: 167-173.When pea plants (Pisum sativum L. cv. Alaska) were grown in controlled environment rooms, a stock plant irradiance of 38 W m~^ decreased the rooting ability ofthe cuttings compared to 16 W m"^. Also the origin of the seeds was of importance. The experiments were done in 1976 (1975 seed lot) and 1979/80 (1978 seed lot). At 38 W m~^ the 1975 seed lot produced 7.2 roots, whereas the 1978 seeds produced 20.7 roots per cutting. The eontent of fructose, glucose, inositol and sucrose was determined from an ethanol extract, and extractable starch from a perehlorie acid extract. The irradiance treatment regulated the carbohydrate content ofthe plants at the time they were made into cuttings. Cuttings from 16 or 38 W m~^ contained initially 6.8 and 8.5% carbohydrate on a dry weight basis respectively. If the plants were not excised to cuttings, a stable level of carbohydrates was maintained throughout the growing period, whereas in the cuttings, the carbohydrate content increased five fold during the rooting period. The content of extractable carbohydrates did not show any correlation to the root initiation process, but might be of importance for the further growth of the new roots. The C/N-ratio of the plants at the time they were made into cuttings reflected the pre-growth condition and was not related to the rooting ability of the cuttings.Additional key-words -C/N-ratio, cuttings, relative growth, root formation, starch, stock plants, sugars. B. Veierskov (present address),the ability of the cuttings to fonn roots. Suggestions n ro u on 1^^.^^ \xsx\ made that a high endogenous ievel of nit-In the process of progagating cuttings, not only the rogen enhances shoot growth, which then diverts the rooting environment, but also the growing condition of carbohydrates and other metabolites from the bases of the stock plant strongly influence the rooting ability of the cuttings, resulting in a reduced ability of the cuttings the cuttings. The first findings of a correlation between to form adventitious roots (Mclntyre 1971, Raid 1924, carbohydrate content and rooting ability in cuttings Starring 1923. Starring (1923) concluded, however, were made by Kraus and Kraybill (1918), and have that it was not the ratio but the actual concentration of lately been reviewed by Haissig (1974). It is not only carbohydrate and nitrogen which was of importance for the carbohydrate content, btit also the ratio between the rooting ability of the cuttings. Haissig (1974) carbohydrate and nitrogen which has been related to suggested, that the difference in C/N-ratio in poorly and

Seasonal variation in sprouting of GF677 peach × almond(Prunus persica × Prunus aygdalus)hybrid root cuttings

“…A relationship between carbohydrates and rooting of cuttings has been reported (Bartolini et al 1996(Bartolini et al , 2000Murai et al 1999), but high carbohydrate content has not always been associated with high rooting and sprouting potential, as this study showed. Hansen et al (1978) and Veierskov et al (1982) observed a negative correlation between carbohydrates and rooting (when light was given to alter stock plant carbohydrate content). However, the observed effect may merely indicate that exposure to high light intensity was intrinsically detrimental to root initiation (see also comments on blanching below).…”

Dynamics of extractable carbohydrates in Pisum sativum. II. Carbohydrate content and photosynthesis of pea cuttings in relation to irradiance and stock plant temperature and genotype

“…The cuttings were rooted in nutrient solutions at an irradiance of either 16 or 38 W m"^ and 20°C. For further information see Veierskov et al (1982). The number of roots formed after a 13 day rooting period was determined.…”

“…The soluble carbohydrates were extracted in 80% ethanol, and their methylsilyl derivatives were analyzed by gas chromatography. The starch was extracted with 35% perchloric acid and analyzed by the anthrone reagent method as previously described by Veierskov et al (1982). For carbohydrate determinations the experiment was replicated three times; in order to determine the number of roots up to seven replications were made.…”

“…of Plant Physiology and B. M. Stummann and K. W. Henningsen, Dept. of Genetics, Royal Veterinary & Agricultural Univ., Thorvaldsensvej 40, DK-1871 Copenhagen V., Denmark. ro u ion jj^g cuttings during the rooting period influences the In an earlier experiment (Veierskov et al 1982) it was number of roots formed in cuttings (Eliasson 1978). demonstrated, that the stoek plant irradiance regulated Exogenously stipplied sucrose promotes root formathe initial carbohydrate content of pea cuttings.…”

“…In etiolated plants the differentiation is were all rooted under the same conditions, and no not the same as in normal light-grown plants, which by obvious relation could be found between the rooting itself might affect the rooting ability. 'Poi Anagallis arability of the ctittings, and their content of extractable vensis stem segments grown in vitro it has been shown carbohydrates (Veierskov et al 1982). Not only tbe ir-by V. Trippi (personal communications) that, in the radiance treatment of stock plants, but also that given to dark, sucrose caused the internodes and leaves to dif-ferentiate in a similar way as segments grown in the light without sucrose.…”