Seed of Cercis siliquastrum L (Leguminosae,Caesalpinioideae): Reserves and their Utilization after Germination

An ultrastructural study on the reserves stored in cotyledons and endosperm and on their utilization after germination has been carried out in Cercis siliquastrum seeds. The observations have shown that all the cotyledonal reserves of proteins and lipids are used during seedling growth. However, inside the endosperm cells only the protein reserves are depleted, and large quantities of lipids remain undigested. In both cell walls and intercellular spaces of the endosperm cells huge masses of polysaccharide reserves are stored. However, only the polysaccharides inserted in the cell walls are dismantled, while those located in the intercellular spaces are not attacked by the lytic enzymes. Some hypotheses regarding the possible roles of those endospermic non-nutritional materials in the strategies of seed germination and seedling growth are suggested.     

紫荆属的系统发育和生物地理学研究

紫荆属（Cercis L.）约含8种,间断分布于亚洲东、西部、欧洲南部和北美。应用核糖体DNA的ITS基因序列研究紫荆属的系统发育关系。在最简约性分析,北美的两个种和南欧、西亚的一个种构成一单系群而隐藏于东亚的种类中。这表明紫荆属北美的种类和南欧、西亚的种类之间的关系比它们的各自与东亚的种类的关系要密切。研究还发现北美洲东、西部的种类可能具较近亲缘。紫荆属以白令陆桥或北大西洋陆桥为迁移途径的可能性似乎都不能排除;北半球的生物地理分布式样可具有复杂的起源。     

Tegumento seminale e germinazione in Cercis siliquastrum L.

Abstract

Seminal integument and germination of Cercis siliquastrum L. – A histological study of the seminal integument of Cercis siliquastrum L. has been carried out, in order to explain whether the obstacle to the germination, removed by a cold-treatment, was caused by a mechanical action of the integument itself. We have noted that both the cold-treated seeds which germinate and the non-treated control seeds which don't germinate show in the long run the same modifications. We have therefore come to the conclusion that the inability to germinate found in the non-treated seeds is not due to the mechanical resistance of the integument and we think it necessary to return to further researches, also at a biochemical level.     

Cytochemical Study on the Dormancy-imposing Endosperm of Cercis siliquastrum

Cytochemical observations indicate the occurrence of leucoanthocyanidinsin the protein bodies of Cercis siliquastrum endosperm; theendosperm cell walls give a positive Mayer's test, indicatingmucopolysac-charides. These results are discussed in relationto the endosperm-imposed dormancy of the seed. Cercis siliquastrum, endosperm-imposed dormancy, leucoanthocyanidins, mucopolysac-charides     

Genetics of seed storage proteins in the love tree Cercis siliquastrum L. (Fabaceae)

The patterns of C. siliquastrum seed storage proteins (cercins) are described using SDS-polyacrylamide gel electrophoresis. The polypeptides detected had very different molecular weights (ranging from 168 to 34 KDa) which, together with their high homogeneity, produced a very good resolution of bands. These proteins could be ascribed to five different loci. The analysis of seed sets of individual trees indicated that the love tree is almost completely autogamous with less than 5% of outcrosses. Although this mode of reproduction seems to produce a decrease in heterozygote frequency among the seeds of the population analysed, the levels of variability detected were very high for an autogamous plant: all of the loci were polymorphic, with a mean heterozygosity of 0.327 and a polymorphic index of 0.412. Protein segregation revealed a strong genetic linkage between three cercin loci (a, c and d) while the other two are independent.     

豆科黄华属植物种子表面特征的研究

在扫描电镜下观察了豆科黄华属Thermopsis 18种植物种子的表面纹饰,发现 T．alpina,T.bar- bata,T．inflata,T．lupinoides,T. licentiana,T.smithiana和T．turkestanica的种子表面为粗网状,T californica,T.divaricarpa,T. macrophylla,T．mollis的种子表面为细网状,T.gracilis,T.montana,T. fabacea的种子表面为相对平滑型纹饰,T．alterniflora的种子表面为不规则条形,T．chinensis的种子表 面为粘膜状,T.rhombifolia的种子表面为条形及 T．viuosa的种子表面为碎屑状纹饰。结果表明黄华属的种子表面特征对属下类群的划分有一定意义,对澄清某些混乱的种有一定价值。     

Reserve carbohydrate metabolism in germinating seeds of trigonella foenum-graecum L. (Leguminosae)

Summary Seeds of Trigonella foenum-graecum are examined light microscopically and by chemical analysis at different stages of germination.In the earliest stages of germination the raffinose family oligosaccharides are metabolised both in the endosperm and in the cotyledons of the seed but there is no change in the appearance, amount or composition of the main carbohydrate reserve, a galactomannan localised in the endosperm. About 18 hours after the emergence of the radicle the endosperm galactomannan begins to be mobilised. In a period of 24 hours the polysaccharide is completely degraded and the breakdown products, mainly galactose and mannose, are absorbed by the cotyledons in which sucrose increases and starch is formed.Mobilisation of the galactomannan is accompanied by the formation in the endosperm of a dissolution zone the form of which implies that the aleurone layer is involved in the degradation process.Part of the work described in this paper was carried out by the author during 1970 at Nottingham University School of Agriculture, Dept. of Applied Biochemistry and Nutrition, Sutton Bonington, England.     

Seed-coat anatomy of the non-pleurogrammic seeds in the tribe Ingeae (Leguminosae,Mimosoideae)

An anatomically complex structure of the seed-coat is a general characteristic of all members of the Leguminosae. Nonetheless, certain genera exhibit a particular type of seed, the “overgrown” seen that has been defined by a developmental criterion and by more simple anatomical features of the seed-coat. Only the last criterion seems suitable for unambiguously distinguishing this type of seed, which is here referred to as “overgrown-like.” This type appears to be apomorphic in the Ingeae (and probably in all the Leguminosae) and likely results from a heterochronic loss of tissue differentiation. Variations in this character may be useful at the generic level, and detailed anatomical observations reveal the occurrence of three distinct patterns. The high degree of correlation with other characters suggests that overgrown-like seeds have evolved separately at least three times in the Ingeae and thatPithecellobium s.s. may be polyphyletic. The overgrown-like seeds are likely to be an adaptive response to wet tropical climates.     

A reappraisal of the free amino acids in seeds of Crotalaria Juncea (Leguminosae)

The seeds of Crotalaria juncea have been reported at different times to contain β-hydroxy-N-methyl-dl-norvaline and δ-hydroxynorleucine, which are isomers. We detected only one non-protein amino acid in seeds obtained from various sources; it has been isolated its identity as δ-hydroxynorleucine confirmed.     

Quantitative determination of calcium oxalate and oxalate in developing seeds of soybean (Leguminosae)

Developing soybean seeds accumulate very large amounts of both soluble oxalate and insoluble crystalline calcium (Ca) oxalate. Use of two methods of detection for the determination of total, soluble, and insoluble oxalate revealed that at +16 d postfertilization, the seeds were 24% dry mass of oxalate, and three-fourths of this oxalate (18%) was bound Ca oxalate. During later seed development, the dry mass of oxalate decreased. Crystals were isolated from the seeds, and X-ray diffraction and polarizing microscopy identified them as Ca oxalate monohydrate. These crystals were a mixture of kinked and straight prismatics. Even though certain plant tissues are known to contain significant amounts of oxalate and Ca oxalate during certain periods of growth, the accumulation of oxalate during soybean seed development was surprising and raises interesting questions regarding its function.     

Untersuchungen über die Endospermschleime der Samen von Cercis siliquastrum L. und Ononis natrix L

Die Samen der Caesalpiniacee Cercis siliquastrum sowie die der Papilionacee Ononis natrix enthalten im unterschiedlich stark entwickelten Endosperm quellbare Zellwandschleime. Die Samen von Ononis natrix besitzen ein vergleichsweise gering entwickeltes Endosperm, jedoch sind die einzelnen Zellen bis zur völligen Reduktion des Lumens schleimerfüllt. Bei Wasserzugabe quellen diese Zellwandschleime beider Arten unterschiedlich stark auf. Die Anfärbbarkeit der Endospermschleime wird anhand der Samen von Cercis siliquastrum für verschiedene Farbstoffe beschrieben. Zur näheren Charakterisierung der Quellbarkeit der Endospermschleime werden Quellungsindex sowie Viskositätsveränderung wäßriger Lösungen untersucht. Besonderes Interesse gilt der Untersuchung der Endospermschleime während der Reifung und Keimung der Samen. Dazu werden aus zerkleinerten unreifen, reifen und gekeimten Samen die Schleimstoffe extrahiert, sauer hydrolysiert und chromatographisch analysiert. Anhand chromatogrammspek-tralphotometrischer Untersuchungen ließ sich für die unterschiedlichen Entwicklungsstadien der Samen das Verhältnis von Galaktose/Mannose ermitteln. Dabei wurden zwischen reifenden, reifen und gekeimten Samen von Ononis natrix nur geringe Schwankungen in der Zusammensetzung des Galaktomannans nachgewiesen. Demgegenüber nimmt bei heranreifenden Samen von Cereis siliquastrum der Galaktosegehalt des Galaktomannans bis zur Reife zu und während der Keimung deutlich ab.     

Effects of seed chilling or GA3 supply on dormancy breaking and plantlet growth in Cercis siliquastrum L.

Germination and post-germination events have been compared in seeds of Cercis siliquastrum whose dormancy was removed by fulfilling the natural chilling requirement or by exogenous GA₃ application.Compared to the chilled ones, the GA₃ treated seeds showed precocious embryo growth and an earlier reserve mobilization, which started before radicle emergence.Although the hormonal application was interrupted at seed germination, the plantlets of Cercis siliquastrum that originated from GA₃-supplied seeds were taller than those from chilled ones. Moreover, they produced a greater number of leaves but a reduced root mass and had some difficulty in maintaining a good water balance.Thus, the treatment of Cercis siliquastrum seeds with exogenous GA₃ broke dormancy and induced germination, but also caused long-lasting consequences on morphogenesis of the growing plantlet.     

A new Astragalus (Leguminosae) from Argentina, notable for placentation of its seeds

From the Patagonian region in ArgentinaAstragalus neocarpus is described and illustrated. The false septum of its fruit is formed by union of the seed-funicles with the endocarp.

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Se describe e ilustraAstragalus neocarpus de la región Patagónica de Argentina, su principal característica distintiva es la morfología del fruto, donde el falso tabique que divide en dos a la cavidad está formado por la unión de largos funículos de las semillas con el endocarpo.

     

Lectin-associated proteins from the seeds of Leguminosae

The seeds of Pisum sativum (pea), Canavalia ensiformis, Vicia faba, Vicia sativa, and Ricinus communis were shown to contain proteins which are associated to the respective lectins (lectin binders). The lectin binders from Pisum sativum and Canavalia ensiformis were studied more closely. Both are single proteins not resembling the variety of membrane glycoproteins found in animals and plants which bind to lectins. The pea lectin binder is a tetrameric glycoprotein composed of identical subunits of the Mr 51 000. Its interaction with the lectin is abolished by acidic buffers or by glucose. The Concanavalin A binder, which does not contain sugar, is composed of one kind of subunit, Mr of 35 000. As in the case of the pea lectin binder, glucose and acid dissociate the lectin-lectin binder complex, but in contrast to the pea lectin binder low NaCl concentrations also cause this effect. During germination and growth, the Concanavalin A binder appears in the roots.     

Ethnobotany ofClitoria (Leguminosae)

Reported economic uses of Clitoria (Leguminosae) are summarized based upon literature reports and label data obtained from examination of over 8000 herbarium vouchers. Reports are categorized by economic use. Most reports are for an African species,C. tematea, presently distributed throughout the tropics. Economic data for 23 species are reported, many for the first time.     

Ulteriori ricerche sulla germinazione di Cercis siliquastrum L. Azione dell'acido gibberellico e ruolo dell'endosperma nel fenomeno della dormienza

Abstract

Further research on the germination of Cercis siliquastrum L. Effect of gibberellic acid (GA₃) and role of endosperm in dormancy.—In order to locate the causes of the dormancy in Cercis siliquastrum L., researches have been carried out also on non-scarified seeds without integument, as well as on isolated embryos.

We have noted that gibberellic acid can substitute the cold treatment to interrupt the dormancy and we have also investigated the optimal concentrations.

The results we have obtained do not show the inhibition to be located in the integument and point out a determinant role of the endosperm.

Histological investigations are being carried out to study better the possible occurrence of a mechanical restraint imposed by the albumen on the non-dormant embryo.