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Reprogramming of cassava (Manihot esculenta) microspores towards sporophytic development.

Perera PI, Ordoñez CA, Dedicova B, Ortega PE - AoB Plants (2014)

Bottom Line: In two cassava genotypes, different developmental stages of microspores were found to initiate sporophytic cell divisions, that is, with tetrads of TMS 60444 and with mid or late uni-nucleate microspores of SM 1219-9.A low frequency of the reprogramming and the presence of non-responsive microspores among the responsive ones in tetrads were found to be related to the viability and exine formation of the microspores.This paves the way for the development of an efficient technique for the production of homozygous lines in cassava.

View Article: PubMed Central - PubMed

Affiliation: Agrobiodiversity Research Area, International Center for Tropical Agriculture, A.A. 6713, Cali, Colombia Present address: Department of Horticulture and Landscape Gardening, Faculty of Agriculture and Plantation Management, Wayamba University, Gonawila, Makandura, Sri Lanka prasanthi1970@yahoo.com.

No MeSH data available.


Related in: MedlinePlus

Scanning electron micrographs showing aspects of cultured tetrads of M. esculenta genotype SM 1219-9. (A) A fresh microspore. Note the differential size and shape of sculptured particles at the aperture (a) area as compared with the rest (scale bar = 10 µm). (B) Close-up view of the pattern of exine sculptures at the aperture of a fresh microspore (scale bar = 10 µm). (C and D) Changes occurring at the aperture in the enlarging microspore. Note that the aperture is opening up and the intine becomes visible (scale bars (C) = 10 µm and (D) = 2 µm). (E) A microspore with protruded intine (pi) through the aperture (scale bar = 10 µm). (F) Close-up view of an aperture where the exine particles are much expanded, the aperture has opened well and where the intine is coming out, making a protrusion. Note the different layers of the exine: end exine (ee), tectum (t) and the sculpture particles (s) located on the tectum (scale bar = 2 µm).
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PLU022F7: Scanning electron micrographs showing aspects of cultured tetrads of M. esculenta genotype SM 1219-9. (A) A fresh microspore. Note the differential size and shape of sculptured particles at the aperture (a) area as compared with the rest (scale bar = 10 µm). (B) Close-up view of the pattern of exine sculptures at the aperture of a fresh microspore (scale bar = 10 µm). (C and D) Changes occurring at the aperture in the enlarging microspore. Note that the aperture is opening up and the intine becomes visible (scale bars (C) = 10 µm and (D) = 2 µm). (E) A microspore with protruded intine (pi) through the aperture (scale bar = 10 µm). (F) Close-up view of an aperture where the exine particles are much expanded, the aperture has opened well and where the intine is coming out, making a protrusion. Note the different layers of the exine: end exine (ee), tectum (t) and the sculpture particles (s) located on the tectum (scale bar = 2 µm).

Mentions: Immature microspores at the mid to late uni-nucleate stage of genotype SM, which were captured in the 70 extract, had exine sculpture particles on their surface, present in an organized manner and forming the typical cassava exine. The exine formed in a regular geometric pattern by the deposition of triangular sculpture elements while the numerous apertures were indicated by the presence of concentrated small sculpture particles (Fig. 7A). The microspores had a fenestrate pore arrangement and were therefore poly-aperturate. The elements located at the aperture were smaller than the rest (Fig. 7B–D). During microspore enlargement, the exine showed interesting changes. With the enlargement of the microspores, the distance between the particles increased, and the intine underlying the exine was clearly visible at the aperture (Fig. 7D). Upon further enlargement, protrusions could be observed at the pores (Fig. 7E). The sculpture elements on the tectum and the absence of a tectum in the pore area were clearly observed when further enlargement of the microspore occurred (Fig. 7F). The three layers of the exine, endexine, columellae and tectum could be identified clearly, as well as the intine. The intine pushed through the pore, producing an oncus on the surface.Figure 7.


Reprogramming of cassava (Manihot esculenta) microspores towards sporophytic development.

Perera PI, Ordoñez CA, Dedicova B, Ortega PE - AoB Plants (2014)

Scanning electron micrographs showing aspects of cultured tetrads of M. esculenta genotype SM 1219-9. (A) A fresh microspore. Note the differential size and shape of sculptured particles at the aperture (a) area as compared with the rest (scale bar = 10 µm). (B) Close-up view of the pattern of exine sculptures at the aperture of a fresh microspore (scale bar = 10 µm). (C and D) Changes occurring at the aperture in the enlarging microspore. Note that the aperture is opening up and the intine becomes visible (scale bars (C) = 10 µm and (D) = 2 µm). (E) A microspore with protruded intine (pi) through the aperture (scale bar = 10 µm). (F) Close-up view of an aperture where the exine particles are much expanded, the aperture has opened well and where the intine is coming out, making a protrusion. Note the different layers of the exine: end exine (ee), tectum (t) and the sculpture particles (s) located on the tectum (scale bar = 2 µm).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4061485&req=5

PLU022F7: Scanning electron micrographs showing aspects of cultured tetrads of M. esculenta genotype SM 1219-9. (A) A fresh microspore. Note the differential size and shape of sculptured particles at the aperture (a) area as compared with the rest (scale bar = 10 µm). (B) Close-up view of the pattern of exine sculptures at the aperture of a fresh microspore (scale bar = 10 µm). (C and D) Changes occurring at the aperture in the enlarging microspore. Note that the aperture is opening up and the intine becomes visible (scale bars (C) = 10 µm and (D) = 2 µm). (E) A microspore with protruded intine (pi) through the aperture (scale bar = 10 µm). (F) Close-up view of an aperture where the exine particles are much expanded, the aperture has opened well and where the intine is coming out, making a protrusion. Note the different layers of the exine: end exine (ee), tectum (t) and the sculpture particles (s) located on the tectum (scale bar = 2 µm).
Mentions: Immature microspores at the mid to late uni-nucleate stage of genotype SM, which were captured in the 70 extract, had exine sculpture particles on their surface, present in an organized manner and forming the typical cassava exine. The exine formed in a regular geometric pattern by the deposition of triangular sculpture elements while the numerous apertures were indicated by the presence of concentrated small sculpture particles (Fig. 7A). The microspores had a fenestrate pore arrangement and were therefore poly-aperturate. The elements located at the aperture were smaller than the rest (Fig. 7B–D). During microspore enlargement, the exine showed interesting changes. With the enlargement of the microspores, the distance between the particles increased, and the intine underlying the exine was clearly visible at the aperture (Fig. 7D). Upon further enlargement, protrusions could be observed at the pores (Fig. 7E). The sculpture elements on the tectum and the absence of a tectum in the pore area were clearly observed when further enlargement of the microspore occurred (Fig. 7F). The three layers of the exine, endexine, columellae and tectum could be identified clearly, as well as the intine. The intine pushed through the pore, producing an oncus on the surface.Figure 7.

Bottom Line: In two cassava genotypes, different developmental stages of microspores were found to initiate sporophytic cell divisions, that is, with tetrads of TMS 60444 and with mid or late uni-nucleate microspores of SM 1219-9.A low frequency of the reprogramming and the presence of non-responsive microspores among the responsive ones in tetrads were found to be related to the viability and exine formation of the microspores.This paves the way for the development of an efficient technique for the production of homozygous lines in cassava.

View Article: PubMed Central - PubMed

Affiliation: Agrobiodiversity Research Area, International Center for Tropical Agriculture, A.A. 6713, Cali, Colombia Present address: Department of Horticulture and Landscape Gardening, Faculty of Agriculture and Plantation Management, Wayamba University, Gonawila, Makandura, Sri Lanka prasanthi1970@yahoo.com.

No MeSH data available.


Related in: MedlinePlus