scholarly journals Morpho-Histology, Endogenous Hormone Dynamics and Transcriptome Profiling in Dacrydium Pectinatum during Male Cone Development

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1598
Author(s):  
Wenju Lu ◽  
Enbo Wang ◽  
Weijuan Zhou ◽  
Yifan Li ◽  
Zhaoji Li ◽  
...  
Keyword(s):  
Pollen Mother Cell ◽  
Mother Cell ◽  
Cell Formation ◽  
Transcriptome Profiling ◽  
Endogenous Hormone ◽  
Male Cone ◽  
Transcriptome Database ◽  
Cone Development ◽  
Hormone Biosynthesis ◽  
External Forces

Dacrydium pectinatum de Laubenfels is a perennial gymnosperm species dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, its natural regeneration is poor. To better understand the male cone development in D. pectinatum, we examined the morphological and anatomical changes, analyzed the endogenous hormone dynamics, and profiled gene expression. The morpho-histological observations suggest that the development of D. pectinatum male cone can be largely divided into four stages: microspore primordium formation (April to May), microspore sac and pollen mother cell formation (July to November), pollen mother cell division (January), and pollen grain formation (February). The levels of gibberellins (GA), auxin (IAA), abscisic Acid (ABA), cytokinin (CTK), and jasmonic acid (JA) fluctuated during the process of male cone development. The first transcriptome database for a Dacrydium species was generated, revealing >70,000 unigene sequences. Differential expression analyses revealed several floral and hormone biosynthesis and signal transduction genes that could be critical for male cone development. Our study provides new insights on the cone development in D. pectinatum and the foundation for male cone induction with hormones and studies of factors contributing to the species’ low rate of seed germination.

Temporal and Spatial Characteristics Endogenous Hormone Regulation During Male Cone Development of Dacrydium pectinatum

2020 ◽  
Author(s):  
Wenju Lu ◽  
Zhaoji Li ◽  
Xiqiang Song ◽  
Jian Wang ◽  
Mingxun Ren ◽  
...  
Keyword(s):  
Pollen Grains ◽  
Endogenous Hormone ◽  
Hormone Regulation ◽  
Rain Forests ◽  
Reproductive Process ◽  
Male Cone ◽  
Cone Development ◽  
Temporal And Spatial ◽  
Temporal And Spatial Characteristics ◽  
External Forces

Abstract Background: Dacrydiumpectinatum de Laubenfels is a perennial gymnosperm dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, natural regeneration is poor. In order to better understand the reproductive process in D. pectinatum, we examined the morphological and anatomical changes during the development of male cone and analyzed the endogenous hormone dynamics.Results: Our study indicates that D. pectinatum male buds become distinguishable in April in tropical montane rain forests, while microspore sac forms in September and pollen mother cell forms and divides in December. Pollen grains mature and disperse in the following February. A mature male cone averages 8.5 mm in length. Level of GA, IAA, ABA and JA and their ratios fluctuated during late August to late November when sporogenous tissues were actively differentiated.Conclusions: The differentiation of sporogenous tissues is accompanied by variations in levels of endogenous hormones (GA, ABA, IAA, and JA) and their balances. The new insights about the cone development in D. pectinatum lay the foundation for future cone induction with hormones and study of factors contributing to the species’ low rate of seed germination.

scholarly journals Meiotic Chromosome Behavior and Capsule Setting in Doritaenopsis Hybrids

2008 ◽  
Vol 133 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Pablo Bolaños-Villegas ◽  
Shih-Wen Chin ◽  
Fure-Chyi Chen
Keyword(s):  
Cell Division ◽  
Pollen Mother Cell ◽  
Chromosome Pairing ◽  
Chromosomal Aberrations ◽  
High Frequency ◽  
Mother Cell ◽  
Seed Set ◽  
Pollen Viability ◽  
High Pollen ◽  
Mother Cells

The development of new cultivars in Doritaenopsis Guillaum. & Lami orchids is often hindered by factors such as low seed count in hybrids. Cytological study may offer the ability to develop new hybrids by revealing cultivars with good chromosome pairing and high pollen viability, which are somewhat difficult to obtain under current breeding programs. Cross pollination, pollen viability, and chromosomal behavior during meiosis were analyzed to reveal the relation between seed fertility and capsule set in Doritaenopsis hybrids. The number of mature capsules harvested and their relative seed content were used as indices of crossing availability. The results of meiosis were evaluated according to pollen viability detected by fluorescein diacetate and quantification of sporad types by acid fuchsin staining. Chromosome number and pairing at meiosis were observed in root tips or in samples of pollen mother cells. A positive relation was found among high seed set, high frequency of viable tetrads, high degree of chromosome pairing, and low frequency of chromosomal aberrations such as inversions and translocations. On the basis of these factors, three types of hybrids could be distinguished. In type one hybrids, chromosomes paired as bivalents, pollen mother cells divided into tetrads, and capsule setting occurred after pollination of pollen acceptors. In type two hybrids, chromosomes remained mainly as univalents that developed into micromeiocytes, pollen mother cell division was disrupted, and seed recovery was low after pollination. Type three hybrids showed chromosomes paired mostly as multivalents, chromosome bridges, pollen mother cell division with massive failure, and little fertility. In Doritaenopsis orchids, high pollen viability and high fertility depends on a high frequency of normal tetrads, and low seed set in cross-pollination is predicted with micronuclei in the end products of meiosis. The occurrence of chromosomal aberrations may suggest a process of genome differentiation that could compromise breeding efforts if not taken into consideration.

Changes in Pattern of Microtubule Organization During Meiosis in Pollen Mother Cell of Autotetraploid Rice

2010 ◽  
Vol 36 (10) ◽  
pp. 1777-1785
Author(s):  
Jin-Hua HE ◽  
Xing-An CHENG ◽  
Zhi-Xiong CHEN ◽  
Hai-Bin GUO ◽  
Xiang-Dong LIU ◽  
...  
Keyword(s):  
Pollen Mother Cell ◽  
Mother Cell ◽  
Microtubule Organization ◽  
Autotetraploid Rice

Relationships between inbreeding, meiotic irregularity, and fertility in alfalfa

1986 ◽  
Vol 28 (1) ◽  
pp. 130-137 ◽  
Author(s):  
S. E. Smith ◽  
R. P. Murphy
Keyword(s):  
Medicago Sativa ◽  
Seed Production ◽  
Inbreeding Depression ◽  
Pollen Mother Cell ◽  
Mother Cell ◽  
Pollen Parent ◽  
Meiotic Behavior ◽  
Negatively Associated ◽  
Meiotic Irregularity ◽  
Medicago Sativa L

Fertility (seed production) in alfalfa (Medicago sativa L.) is severely depressed by inbreeding; however, little is known of the factors directly responsible for this depression. Irregularities in meiotic behavior could be partially responsible for the inbreeding depression in fertility observed. This study considered relationships between fertility, inbreeding, and irregularity in microsporogenesis. Fertility declined markedly with inbreeding in the materials examined (S0–S3). Irregularity in microsporogenesis, as measured by the percent irregular quartets, (i.e., quartets with micronuclei, supernumerary microspores, or irregular cytokinesis) increased significantly with inbreeding. Increases in quartet irregularity were associated with increases in the number of univalents per pollen mother cell observed at metaphase I. Considering all materials studied, the percentage of irregular quartets was negatively and significantly correlated with fertility as both a seed and a pollen parent. In more detailed analyses, it was observed that the percent irregular quartets was negatively associated with fertility as a pollen parent only when levels of irregularity were relatively high. No association was observed between the percent irregular quartets and fertility when levels of irregularity were relatively low.Key words: Medicago, microsporogenesis, seed production, breeding, fertility.

Use of Pectinase in Pollen Tube and Pollen Mother Cell Smears

1959 ◽  
Vol 34 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Kamla K. Pandey ◽  
Robert D. Henry
Keyword(s):  
Pollen Tube ◽  
Pollen Mother Cell ◽  
Mother Cell
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