Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle
Two accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequ...
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| Language: | English |
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Wiley
2012-01-01
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| Series: | The Scientific World Journal |
| Online Access: | http://dx.doi.org/10.1100/2012/691545 |
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| author | Puneet Kumar Vijay Kumar Singhal |
| author_facet | Puneet Kumar Vijay Kumar Singhal |
| author_sort | Puneet Kumar |
| collection | DOAJ |
| description | Two accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequently n pollen grains and 100% pollen fertility. Second accession from the same locality revealed the erratic meiosis characterized by the presence of all the 28 chromosomes as univalents in meiocytes at metaphase I. Univalent chromosomes failed to segregate during anaphases and produced restitution nuclei at meiosis I and II. These restitution nuclei resulted into dyads and triads which subsequently produced two types of apparently fertile pollen grains. On the basis of size, the two types of pollen grains were categorized as n (normal reduced) and 2n (unreduced, 1.5-times larger than the n pollen grains). The estimated frequency of 2n pollen grains from dyads and triads (61.59%) was almost the same as that of the observed one (59.90%), which indicated that 2n pollen grains in R. laetus were the result of dyads and triads. The present paper herein may provide an insight into the mechanisms of the formation of various intraspecific polyploids through sexual polyploidization in R. laetus. |
| format | Article |
| id | doaj-art-6c8f0417311048f0b85f1f7b6e4b4810 |
| institution | Kabale University |
| issn | 1537-744X |
| language | English |
| publishDate | 2012-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | The Scientific World Journal |
| spelling | doaj-art-6c8f0417311048f0b85f1f7b6e4b48102025-02-03T01:23:30ZengWileyThe Scientific World Journal1537-744X2012-01-01201210.1100/2012/691545691545Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex RoylePuneet Kumar0Vijay Kumar Singhal1Department of Botany, Punjabi University, Patiala 147 002, Punjab, IndiaDepartment of Botany, Punjabi University, Patiala 147 002, Punjab, IndiaTwo accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequently n pollen grains and 100% pollen fertility. Second accession from the same locality revealed the erratic meiosis characterized by the presence of all the 28 chromosomes as univalents in meiocytes at metaphase I. Univalent chromosomes failed to segregate during anaphases and produced restitution nuclei at meiosis I and II. These restitution nuclei resulted into dyads and triads which subsequently produced two types of apparently fertile pollen grains. On the basis of size, the two types of pollen grains were categorized as n (normal reduced) and 2n (unreduced, 1.5-times larger than the n pollen grains). The estimated frequency of 2n pollen grains from dyads and triads (61.59%) was almost the same as that of the observed one (59.90%), which indicated that 2n pollen grains in R. laetus were the result of dyads and triads. The present paper herein may provide an insight into the mechanisms of the formation of various intraspecific polyploids through sexual polyploidization in R. laetus.http://dx.doi.org/10.1100/2012/691545 |
| spellingShingle | Puneet Kumar Vijay Kumar Singhal Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle The Scientific World Journal |
| title | Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle |
| title_full | Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle |
| title_fullStr | Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle |
| title_full_unstemmed | Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle |
| title_short | Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28) of Ranunculus laetus Wall. ex Royle |
| title_sort | erratic male meiosis resulting in 2n pollen grain formation in a 4x cytotype 2n 28 of ranunculus laetus wall ex royle |
| url | http://dx.doi.org/10.1100/2012/691545 |
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