How Many Different Kinds of Meiotic Abnormalities Could Be Found in a Unique Endogamous Maize Plant?

Utsunomiya, Karina Sayuri; Bione, Nilton Cesar Pires; Pagliarini, Maria Suely

doi:10.1508/cytologia.67.169

Cited by 30 publications

(20 citation statements)

References 14 publications

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“…The behavior of laggards is characteristic in that they generally lead to micronuclei formation (Badr 1983, 1987, Kumar and Rai 2006. Micronuclei also arise if laggards or nonoriented chromosomes fail to reach the poles in time to be in the main telophase nucleus (Utsunomiya et al 2002). Micronuclei derived from a whole chromosome, due to lagging chromosomes, have a higher probability to survive and undergo condensation in synchrony with the main nuclei than micronuclei derived from a chromosome fragment (Gustavino et al 1987).…”

Section: Discussionmentioning

confidence: 99%

Cytological Effects of Gamma Radiation and Its Impact on Growth and Yield of M1 and M2 Plants of Cowpea Cultivars

2014

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SummaryThis study aimed at investigating the changes imposed by gamma radiation in mitotic activities and the chromosomes as well as the vegetative criteria and yield of M1 and M2 plants of five cowpea cultivars. Seeds of cultivars (Kaha 1, Dokki 331, Azmerly, Cream 7 and Giza 6) were exposed to levels of γ-radiation ranging from 50 to 300 Gy. Low levels of γ-radiation enhanced mitotic activity and resulted in significant increase in chromosomal abnormalities in the root tip cells of M1 and M2 plants. The percentage of abnormalities varied among the varieties and was generally lower in M2 plants compared to M1 plants. The 50-Gy and 100-Gy doses of γ-radiation induced positive effects on plant growth and yield of M1 plants, while the 300 Gy of γ-radiation caused detrimental damage on three cultivars (Dokki 331, Azmerly and Cream 7), which failed to grow to flowering. More pronounced improvements in growth and yield were recorded in M2 plants; the increase in growth and yield was often associated with increased mitotic activity and the occurrence of chromosomal abnormalities, indicating that γ-radiation-induced chromosomal abnormalities are not likely to be associated with negative effects on growth or yield. Based on the calculated yield index, 50 Gy of γ-radiation may be used to improve the yield of three varieties (Dokki 331, Azmerly and Cream 7) and the 100 Gy dose may be recommended for improving the yield of the two varieties, Kaha 1 and Giza 6.

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Section: Discussionmentioning

confidence: 99%

Cytological Effects of Gamma Radiation and Its Impact on Growth and Yield of M1 and M2 Plants of Cowpea Cultivars

2014

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“…Pagliarini (1990) reported that laggards may result from late chiasma terminalization. Ascending chromosomes are the result of precocious migration and, according to Utsunomiya et al (2002), generally consist of univalent chromosomes formed during late prophase stages by precocious chiasma terminalization in early metaphase I or may even result from low chiasma frequency or from the presence of asynaptic or desynaptic genes (Pagliarini 2000). Laggards and non-oriented chromosomes may produce micronuclei, if they fail to reach the poles in time to be included in the main telophase nucleus (Koduru and Rao 1981;Utsunomiya et al 2002), leading to the formation of micro-pollen, and probably to gametes with unbalanced chromosome numbers (Mansuelli et al 1995), such as aneuploids (Defani-Scoarize et al 1995).…”

Section: Laggard Chromosomesmentioning

confidence: 99%

An overview on cytogenetics of the genusOnobrychis(Fabaceae) with special reference toO.sect.Hymenobrychisfrom Iran

2012

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“…Un-oriented bivalents have also been reported at metaphase-I along with the chromatin stickiness, which may be related to impaired attachment of kinetochore to the spindle fibre or due to late chiasma terminalization and may thus result in laggards (Nicklas andWard 1994, Pagliarini 2000). The laggards, failing to reach the poles, generally form micronuclei (Utsunomiya et al 2002) or micro-pollen/uneven gametes. According to Dowd et al (1986), irregularity in mircosporogenesis (formation of micronuclei at telophase) could be due to patchy breakage of chromatin bridge at anaphase-I.…”

Section: Meiotic Abnormalitiesmentioning

confidence: 99%

Anomalous Chromosomal Behaviour and Chromosomal Data in Some Members of Subclass Gamopetalae from District Hamirpur (H. P.), India

et al. 2016

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SummaryThe present study pertains to the cytomorphology of 19 species belonging to nine families of the subclass Gamopetalae from Hamirpur district (H. P.). Out of these, 5 species are new or varied chromosomes reports. Campanula benthamii (2n=2x=28) and Leucas hyssopifolia (2n=2x= 22) are the first ever chromosome counts for the species. Spilanthes acmella (2n=6x=78) and Borreria articularis (2n=4x=52) are varied cytotypes. Meanwhile, the B chromosome is reported for the first time in Leucas lanata (2n=22+0-1B). Almost all of the accessions (with disparity in percentage) show laggards, chromosome stickiness and cytomixis from early prophase to telophase-II, leading to the formation of aneuploid cells or meiocytes with double the normal chromosome number. Such meiotic abnormalities produce unreduced pollen grains and reduce pollen viability.Key words Cytology, Gamopetalae, Hamirpur, Meiotic abnormality.Hamirpur district is situated between 76 31′ East longitude and 31 38′ North latitude. The track is hilly covered by the Shivalik range, and the elevation varies from 450 to 1100 m. Hamirpur district is the smallest district of Himachal Pradesh, which possesses unique medicinal wealth and diverse flora. Due to favorable climatic conditions, this region acts as medicinal hotspots, provides raw material for pharmaceutical, phytochemical, food, flavorings and cosmetic industries. The rich floral diversity of the district has previously attracted the attention of many ethnobotanist. Sharma et al. (2013) divulge 91 species and are considered as one of the major contributors, followed by Kumar and Choyal (2012), Seema et al. (2012) and Devi et al. (2012) who do the same for 36, 22 and 20 species, respectively. As a part of our research thrust, the cytomorphology of many species of Gamopetalae has been explored from higher altitudes of the Northwestern Himalayas by many workers. Major contributions are made by Gupta et al.

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How Many Different Kinds of Meiotic Abnormalities Could Be Found in a Unique Endogamous Maize Plant?

Cited by 30 publications

References 14 publications

Cytological Effects of Gamma Radiation and Its Impact on Growth and Yield of M1 and M2 Plants of Cowpea Cultivars

Cytological Effects of Gamma Radiation and Its Impact on Growth and Yield of M1 and M2 Plants of Cowpea Cultivars

An overview on cytogenetics of the genusOnobrychis(Fabaceae) with special reference toO.sect.Hymenobrychisfrom Iran

Anomalous Chromosomal Behaviour and Chromosomal Data in Some Members of Subclass Gamopetalae from District Hamirpur (H. P.), India

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