Pattern of the Cyanide-Potential in Developing Fruits

Abstract

The absolute cyanide content of developing fruits was determined in Costa Rican wild lima beans (Phaseolus lunatus), oil flax (Linum usitatissimum), and bitter almonds (Prunus amygdalus). The cyanide potential (HCN-p) of the lima bean and the almond fruit began to increase shortly after anthesis and then stopped before fruit maturity. In contrast, the flax inflorescence had a higher HCN-p in absolute terms than the mature flax fruit. At all times of its development the bean fruit contained the monoglucosides linamarin and lotaustralin. The almond and the flax fruits contained, at anthesis, the monoglucosides prunasin, and linamarin and lotaustralin, respectively, while, at maturity, only the corresponding diglucosides amygdalin, and linustatin and neolinustatin, respectively, were present. bitter almond (Prunus amygdalus) from anthesis to the mature fruit. MATERIAL AND METHODS Source of Plant MaterialThe same collection of wild lima bean seed (Phaseolus lunatus L.) described by Frehner and Conn (6) Lima bean plants were grown in growth chambers from seeds in plastic pots (3 seeds per pot) using standard soil.Wooden rods were used to support the plants. The growth chambers were set to 10 h light (mixed incandescent and mercury vapor lamps) at 26°C and a RH of about 60%; at night the temperature was 1 8°C and the humidity about 80%. Flax was grown in growth chambers in groups of three plants per pot containing vermiculite. These chambers were set to 16 h light (mixed incandescent and fluorescent lamps) at 18°C; at night the temperature setting was 18°C. Humidity was not controlled in this experiment. All the plants were watered three times each week and received commercial liquid fertilizer once a week. The almond trees were neither watered nor fertilized. SamplingThe date ofanthesis ofindividual lima bean and flax flowers was recorded by inspection three times a week during a period of 5 weeks. Each time a small, dated tag was hung around stems bearing newly blossoming flowers; other 1 or 2 d old inflorescences not required for our experiments were removed so that only tagged fruits were allowed to develop. Mature and immature tagged fruits were removed from the parent plant, weighed, frozen in liquid N2, and lyophilized. Units consisting of whole pots were completely processed on the same day. Sufficiently developed lima bean fruits were divided into seeds and fruit walls prior to weighing (Fig. 1)

Your Beans of the Last Harvest and the Possible Adoption of Bright Ideas

“…Although this point has already been discussed elsewhere [ 121 ], it might be worth updating. Eating young pods is an option, before antinutritional factors start accumulating in the seeds in the second fortnight close to maturity (for example, cyanide content in wild Lima bean: Frehner et al [ 122 ]; or lectins in P. lunatus : Martin et al [ 123 ]). In doing so, would-be domesticators are just following the example of birds (in spite of the differences in digestive tracks), as populations of wild beans show in pods damages by birds (Debouck et al; also vouchers CR235450, US3168338 at these Herbaria) [ 124 ].…”

Use of recessive homozygous genotypes to assess genetic control of kernel bitterness in almond

“…D.A. Webb], as in other Prunus species, bitter flavour of the kernel is due to the cyanoglucoside amygdalin (McCarty et al 1952;Conn 1980;Frehner et al 1990;Arrá zola 2002). In bitter kernels, amygdalin is synthesised from prunasin, which comes from the mother plant (Frehner et al 1990), i.e.…”

Tri-Trophic Level Impact of Host Plant Linamarin and Lotaustralin on Tetranychus urticae and Its Predator Phytoseiulus persimilis

“…Lima beans (Fabaceae, Phaseolus lunatus L.) are among the 2,500 plant species capable of producing cyanogenetic glycosides such as linamarin (Frehner and Conn, 1987;Poulton, 1990) and lotaustralin (Frehner et al, 1990). Linamarin and lotaustralin are derivatives of valine and isoleucine, respectively (Conn, 1979;Forslund et al, 2004).…”