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Microsporogenesis and pollen formation in cassava  

British Library Electronic Table of Contents (United Kingdom)

This article describes the complete microsporogenesis and pollen formation in cassava (Manihot esculenta Crantz) at the various developmental stages (pollen mother cell, meiosis, tetrads, early free spore, mid uninucleate, late uninucleate, binucleate and mature pollen grain). Light microscopy, transmission electron microscopy and confocal laser scanning microscopy were used for the study. Floral bud size and other inflorescence characteristics were correlated with specific stages of the microspore development. This association allows a rapid selection of floral buds with similar microspore developmental stages, useful when a large number of homogeneous cells are needed for analysis and for in vitro induction of androgenesis. This article also compares methods for digestion the exine wall ...

2011-01-01

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Identification of actively filling sucrose sinks. [Solanum tuberosum; Phaseolus lunatus; Manihot esculenta; Liquidambar styraciflua L. ; Carya illinoinensis  

Energy Technology Data Exchange (ETDEWEB)

Certain actively filling plant sucrose sinks such as a seed, a tuber, or a root can be identified by measuring the uridine diphosphate and pyrophosphate-dependent metabolism of sucrose. Sucrolysis in both active and quiescent sucrose sinks was tested and sucrose synthase was found to be the predominant sucrose breakdown activity. Sucrolysis via invertases was low and secondary in both types of sinks. Sucrose synthase activity dropped markedly, greater than fivefold, in quiescent sinks. The test are consistent with the hypothesis that the sucrose filling activity, i.e. the sink strength, of these plant sinks can be measured by testing the uridine diphosphate and pyrophosphate-dependent breakdown of sucrose. Measuring the initial reactions of sucrolysis shows much promise for use in agriculture crop and tree improvement research as a biochemical test for sink strength.

1989-04-01

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Studies on a Factor in Sweet Potato Root Which Agglutinates Spores of Ceratocystis fimbriata, Black Rot Fungus 1  

Science.gov (United States)

A factor which agglutinated the spores of Ceratocystis fimbriata in the presence of Ca2+ was purified from sweet potato (Ipomea batatas Lam cv. Norin[1]) root. Element composition of the purified factor was as follows; analysis found: C (29.8%), H (3.97%), O (65.34%), N (0.81%): calculated for C43H69O70N1: C (30.02%), H (4.01%), O (65.15%), N (0.81%). The factor was mainly composed of galacturonic acid (53% of dry weight) and contained arabinose, fucose, and unidentified component as minor components. The factor also agglutinated A-, B-, AB-, and O types of human erythrocytes to almost the same degree in the presence of Ca2+. The differential spore-agglutinating activity of the factor depended on the pH of the assay medium; it agglutinated similarly the germinated spores of sweet potato and coffee strains at pH 7.5 and 5.5, whereas it displayed a distinct differential agglutinating activity at pH 6.5. The factor was assayed for spore-agglutinating activity at pH 6.5, using the ...

1982-02-01