SOLUBLE SACCHARIDES AND CYCLITOLS IN ALFALFA (MEDICAGO-SATIVA L) SOMATIC EMBRYOS, LEAFLETS, AND MATURE SEEDS

Soluble carbohydrates were identified and quantified during developmen t, maturation and desiccation of somatic embryos of alfalfa (Medicago saliva L.) and compared to soluble carbohydrates in leaflets and matur e seeds, to relate changes in soluble carbohydrates to maturation even ts. Somatic embryos have elevated levels of sucrose. However, in contr ast to mature seeds, alfalfa somatic embryos do not accumulate D-pinit ol or the galactosyl derivatives of D-pinitol such as galactopinitol A , galactopinitol B and ciceritol. Lower levels of stachyose accumulate during maturation of somatic embryos, but stachyose increases to leve ls in mature seeds during desiccation of somatic embryos. When stachyo se accumulation is limited in somatic embryos, galactinol and digalact osyl myo-inositol increase. Reducing sugars decline to low levels duri ng desiccation of somatic embryos and sucrose: oligosaccharide ratio d ecreases from 2.7 to 0.9, approaching the ratio 0.2 to 0.3 in mature d ry seeds, Except for the lack of pinitol and galactosyl pinitols, chan ges in soluble carbohydrates during the maturation and desiccation of alfalfa somatic embryos are typical of changes occurring in mature see ds that have been reported to be associated with desiccation tolerance and storability.