Cytological implications in interspecific cross of Arachis involving Arachis hypogaea var VRI 2 and Arachis stenosperma

2018 ◽  
Author(s):  
S. Saravanan
Keyword(s):  
Arachis Hypogaea ◽  
Pollen Fertility ◽  
Slow Growth ◽  
Interspecific Cross ◽  
Breeding Strategy ◽  
Pollen Grain ◽  
Phenotypic Traits ◽  
Specific Hybridization ◽  
Sterile Pollen ◽  
Meiotic System

Unstable triploid and sterile derivatives were obtained upon inter-specific hybridization of Arachis hypogaea var VRI 2 (2n=4x=40) and Arachis stenosperma (2n=2x=20). Chromosomal doubling was resorted using colchicine enabling doubling the ploidy level of this triploid (3x) to get an unstable hexaploid derivative. The manuscript presents the cyto-morphological features of the unstable derivatives to frame a suitable breeding strategy for evolving the stable culture tolerant to major foliar diseases. Phenotypic traits like leaf colour, length and width of calyx tube, poor pollen fertility and abortive ovarian system were found to be dominant in the triploid. Chromosome doubled triploid progeny possessed leaves with larger veins, semi spreading habit, slow growth, shriveled anthers and improved pollen fertility as compared to triploid. While the normal meiotic behaviour witnessed among parents, the abnormal meiotic system as evidenced from the formation of trivalents and quadrivalents among triploid and hexaploid derivatives. Abnormal sporads also recorded among triploid and hexaploid leading to formation of sterile pollen grain.

scholarly journals Geographical variation in postzygotic isolation and its genetic basis within and between two Mimulus species

2010 ◽  
Vol 365 (1552) ◽  
pp. 2469-2478 ◽  
Author(s):  
Noland H. Martin ◽  
John H. Willis
Keyword(s):  
Pollen Fertility ◽  
Genetic Basis ◽  
Interspecific Cross ◽  
Local Scale ◽  
Interspecific Crosses ◽  
Postzygotic Isolation ◽  
Hybrid Fitness ◽  
Pure Species ◽  
Geographical Scale ◽  
Germination Success

The aim of this study is to investigate the evolution of intrinsic postzygotic isolation within and between populations of Mimulus guttatus and Mimulus nasutus . We made 17 intraspecific and interspecific crosses, across a wide geographical scale. We examined the seed germination success and pollen fertility of reciprocal F 1 and F 2 hybrids and their pure-species parents, and used biometrical genetic tests to distinguish among alternative models of inheritance. Hybrid seed inviability was sporadic in both interspecific and intraspecific crosses. For several crosses, Dobzhansky–Muller incompatibilities involving nuclear genes were implicated, while two interspecific crosses revealed evidence of cytonuclear interactions. Reduced hybrid pollen fertility was found to be greatly influenced by Dobzhansky–Muller incompatibilities in five out of six intraspecific crosses and nine out of 11 interspecific crosses. Cytonuclear incompatibilities reduced hybrid fitness in only one intraspecific and one interspecific cross. This study suggests that intrinsic postzygotic isolation is common in hybrids between these Mimulus species, yet the particular hybrid incompatibilities responsible for effecting this isolation differ among the populations tested. Hence, we conclude that they evolve and spread only at the local scale.

scholarly journals Quantitative methods in microscopy to assess pollen viability in different plant taxa

2020 ◽  
Vol 33 (3-4) ◽  
pp. 205-219
Author(s):  
Lorenzo Ascari ◽  
Cristina Novara ◽  
Virginia Dusio ◽  
Ludovica Oddi ◽  
Consolata Siniscalco
Keyword(s):  
Statistical Power ◽  
Quantitative Methods ◽  
Pollen Viability ◽  
Crop Improvement ◽  
Pollen Grains ◽  
Pollen Sterility ◽  
Pollen Grain ◽  
Automated Image Analysis ◽  
Future Research ◽  
Sterile Pollen

AbstractHigh-quality pollen is a prerequisite for plant reproductive success. Pollen viability and sterility can be routinely assessed using common stains and manual microscope examination, but with low overall statistical power. Current automated methods are primarily directed towards the analysis of pollen sterility, and high throughput solutions for both pollen viability and sterility evaluation are needed that will be consistent with emerging biotechnological strategies for crop improvement. Our goal is to refine established labelling procedures for pollen, based on the combination of fluorescein (FDA) and propidium iodide (PI), and to develop automated solutions for accurately assessing pollen grain images and classifying them for quality. We used open-source software programs (CellProfiler, CellProfiler Analyst, Fiji and R) for analysis of images collected from 10 pollen taxa labelled using FDA/PI. After correcting for image background noise, pollen grain images were examined for quality employing thresholding and segmentation. Supervised and unsupervised classification of per-object features was employed for the identification of viable, dead and sterile pollen. The combination of FDA and PI dyes was able to differentiate between viable, dead and sterile pollen in all the analysed taxa. Automated image analysis and classification significantly increased the statistical power of the pollen viability assay, identifying more than 75,000 pollen grains with high accuracy (R2 = 0.99) when compared to classical manual counting. Overall, we provide a comprehensive set of methodologies as baseline for the automated assessment of pollen viability using fluorescence microscopy, which can be combined with manual and mechanized imaging systems in fundamental and applied research on plant biology. We also supply the complete set of pollen images (the FDA/PI pollen dataset) to the scientific community for future research.

scholarly journals Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

Genetika ◽  
2006 ◽  
Vol 38 (2) ◽  
pp. 159-167 ◽  
Author(s):  
Sreten Terzic ◽  
Jovanka Atlagic ◽  
Dejana Pankovic
Keyword(s):  
Helianthus Annuus ◽  
Ssr Markers ◽  
Interspecific Cross ◽  
F1 Hybrids ◽  
Interspecific Crosses ◽  
Phenotypic Traits ◽  
F1 Hybrid ◽  
Helianthus Annuus L ◽  
Hybrid Plants ◽  
Pollen Vitality

Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR) polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

scholarly journals Saccharomyces Cerevisiae Strains Selected from Nature Significantly Increased the Production of 2-Phenylethanol Through Protoplast Fusion

2021 ◽  
Author(s):  
Lucheng Lin ◽  
Zhiwei Xu ◽  
Weixia Wang ◽  
Kun Wang ◽  
Tingheng Zhu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protoplast Fusion ◽  
Agar Plate ◽  
Breeding Strategy ◽  
Phenotypic Traits ◽  
Industrial Strain ◽  
Genetic Traits ◽  
Good Tolerance ◽  
Yeast Strains ◽  
Thermotolerant Strain

Abstract Background: 2-Phenylethanol (2-PE) is an aromatic alcohol with rose fragrance, which is widely used as an additive in food, tobacco and daily chemical industries. Yeast is the main microorganism producing natural 2-PE, but it is limited by low production and weak tolerance. Nature and fermented products is a resource treasury of yeasts with excellent traits. Screening strains with good phenotypic traits and conducting breeding by cell fusion for genetic pyramiding is an effective way to improve strains. Results: In this study, 25 strains of 2-PE-producing yeasts were isolated from Chinese brewed samples. Three Saccharomyces cerevisiae strains with good traits in tolerance and 2-PE titre were screened out. The strain LSC-1 produces 2-PE of 3.41 g/L with an increase of 9.3% compared to the industrial strain CWY132. The strain NGER shows good tolerance to 2-PE at the concentration of 3.60 g/L in agar plate, and the thermotolerant strain S.C-1 shows growth ability at 41℃. Two rounds of protoplast fusion were performed with these three parent strains for pyramiding of traits. A fusant strain RH2-16 with high 2-PE titre and increased tolerance was obtained. Using 5g/L L-phenylalanine as the precursor substrate, the maximum titre of 2-PE produced by the RH2-16 strain through fermentation and transformation is 4.31 g/L, and the average titre is 4.04 g/L. The molar conversion rate of L-Phe reached 115% in 36 h. Compared to the parental strain LSC-1 and the industrial strain CWY132, 2-PE titre in RH2-16 increased by 26.4% and 38.1%, respectively.Conclusion: Diversified S. cerevisiae strains with different traits can be isolated from the brewing related samples. Protoplast fusion technology can effectively pyramid excellent genetic traits and breed yeast strains with significantly improved tolerance and 2-PE titre. Our research provided a breeding strategy for S. cerevisiae and a strain for industrial production of 2-PE.

Inheritance of phenotypic traits in the progeny of a Ceratocystis interspecific cross

2018 ◽  
Vol 122 (7) ◽  
pp. 717-729 ◽  
Author(s):  
Arista Fourie ◽  
Michael J. Wingfield ◽  
Brenda D. Wingfield ◽  
Magriet A. van der Nest ◽  
M. Theodor Loots ◽  
...  
Keyword(s):  
Interspecific Cross ◽  
Phenotypic Traits

scholarly journals Disturbances in microsporogenesis and pollen grain development in Gagea lutea (L.) Ker. Gaw.

2012 ◽  
Vol 59 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Ewa Szczuka ◽  
Jerzy Bohdanowicz ◽  
Joanna Świerczyńska ◽  
Jolanta Sobieska ◽  
Jacek Pietrusiewicz
Keyword(s):  
Abiotic Factors ◽  
Pollen Grains ◽  
Pollen Grain ◽  
External Factors ◽  
Grain Development ◽  
Excitation Light ◽  
Gagea Lutea ◽  
Microtubular Cytoskeleton ◽  
Sterile Pollen ◽  
Autumn And Winter

The meiotic division of microsporocytes and pollen grain development in <i>Gagea lutea</i> (L.) Ker.-Gaw. (Liliaceae) with fluorescence microscope (excitation light 400 nm) was observed after squashing the anthers in DAPI solution (fluorochrom dying DNA). Up to 70% of microsporocytes and pollen grains during the microsporogenesis and pollen grain development take a regular course. In the remaining microsporocytes and pollen grains (30%) the disturbances in course of both processes were observed. The most often observed disturbances are "late" chromosomes and a presence of micronuclei. The divisions of microsporocytes in the anther loculi show a big asynchrony, which, like the disturbances during the course of microsporogenesis and pollen grain development, may be caused by the external factors. The microsporogenesis takes place during autumn and winter months: the pollen grains develop in winter. At this time the dividing microsporocytes and developing pollen grains are under the influence of abiotic factors as low temperature and a lack of water. These factors disturb the formation of microtubular cytoskeleton of the dividing microsporocytes and pollen grains, which causes the formation of sterile pollen grains.

scholarly journals Saccharomyces Cerevisiae Strains Selected From Nature Significantly Increased the Production of 2-Phenylethanol Through Protoplast Fusion

2021 ◽  
Author(s):  
Lucheng Lin ◽  
Zhiwei Xu ◽  
Weixia Wang ◽  
Kun Wang ◽  
Tingheng Zhu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protoplast Fusion ◽  
Agar Plate ◽  
Breeding Strategy ◽  
Phenotypic Traits ◽  
Industrial Strain ◽  
Genetic Traits ◽  
Fusion Strain ◽  
Thermotolerant Strain ◽  
Key Enzyme

Abstract Background: 2-Phenylethanol (2-PE) is an aromatic alcohol with rose fragrance, which is widely used as an additive in food, tobacco and daily chemical industries. Yeast is the main microorganism producing natural 2-PE, but it is limited by low yield and weak tolerance. Nature and fermented products is a resource treasury of yeasts with excellent traits. Screening strains with good phenotypic traits and conducting breeding by cell fusion for genetic pyramiding is an effective way to improve strains. Results: In this study, 25 strains of 2-PE-producing yeasts were isolated from Chinese brewed samples. Three Saccharomyces cerevisiae strains with good traits in tolerance and 2-PE yield were screened out. The strain LSC-1 produces 2-PE of 3.41 g/L with an increase of 9.3% compared to the industrial strain CWY132. The strain NGER shows good tolerance to 2-PE at the concentration of 3.60 g/L in agar plate, and the thermotolerant strain S.C-1 shows growth ability at 41℃. Two rounds of protoplast fusion were performed with these three parent strains for pyramiding of traits. A fusion strain RH2-16 with high 2-PE yield and increased tolerance was obtained. Using 5 g/L L-phenylalanine as the precursor, RH2-16 produced 2-PE of 4.31 g/L through fermentation conversion and the molar conversion rate of L-Phe reached 115% in 36 h. Compared to the yield of the parental strain LSC-1 and the industrial strain CWY132, 2-PE in RH2-16 increased by 26.4% and 38.1%, respectively. Overexpression of the key enzyme genes ARO8, ARO10, and ADH2 in the Ehrlich pathway in RH2-16 did not increase 2-PE production.Conclusion: Diversified S.cerevisiae strains with different traits can be isolated from the brewing related samples. Protoplast fusion technology can effectively pyramid excellent genetic traits and breed yeast strains with significantly improved tolerance and 2-PE yield. Our research provided a breeding strategy for S.cerevisiae and a strain for industrial production of 2-PE. Overexpression of the key enzyme genes in 2-PE synthesis pathway does not necessarily improve increase production.

scholarly journals Genetic diversity and population structure of groundnut (Arachis hypogaea L.) accessions using phenotypic traits and SSR markers: implications for rust resistance breeding

2020 ◽  
Author(s):  
Happy Daudi ◽  
Hussein Shimelis ◽  
Isack Mathew ◽  
Richard Oteng‐Frimpong ◽  
Chris Ojiewo ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Arachis Hypogaea ◽  
Ssr Markers ◽  
Leaf Spot ◽  
Polymorphic Information Content ◽  
Sub Saharan Africa ◽  
Phenotypic Traits ◽  
Genotypic Differences ◽  
Environment Interaction ◽  
Late Leaf Spot

AbstractGroundnut (Arachis hypogaea L.) is a multi-purpose legume serving millions of farmers and their value chain actors globally. Use of old poor-performing cultivars contributes to low yields (< 1 t/ha) of groundnut in sub-Saharan Africa including Tanzania. The objectives of this study were to determine the extent of genetic variation among diverse groundnut collections using phenotypic traits and simple sequence repeat (SSR) markers to select distinct and complementary genotypes for breeding. One hundred and nineteen genotypes were evaluated under field conditions for agronomic traits and susceptibility to rust and leaf spot diseases. The study was conducted in two locations across two seasons. In addition, the 119 accessions were profiled with 13 selected SSR markers. Genotype and genotype by environment interaction effects were significant (p < 0.05) for days to flowering (DTF), late leaf spot score at 85 and 100 days after planting, pod yield (PDY), kernel yield (KY), hundred seed weight (HSW) and shelling percentage (SP). Principal components analysis revealed that plant stand, KY, SP, NPP (number of pods per plant), late leaf spot and rust disease scores accounted for the largest proportion of the total variation (71.9%) among the tested genotypes. Genotypes ICGV-SM 08587 and ICGV-SM 16579 had the most stable yields across the test environments. Moderate genetic variation was recorded with mean polymorphic information content of 0.34 and gene diversity of 0.63 using the SSR markers. The majority (74%) of genotypes showed high membership coefficients to their respective sub-populations, while 26% were admixtures after structure analysis. Much of the variation (69%) was found within populations due to genotypic differences. The present study identified genotypes ICGV-SM 06737, ICGV-SM 16575, ICG 12725 and ICGV-SM 16608 to be used for development of mapping population, which will be useful for groundnut improvement. This study provided a baseline information on characterization and selection of a large sample of groundnut genotypes in Tanzania for effective breeding and systematic conservation.

Pollination.

2021 ◽  
Author(s):  
Vicki Cottrell
Keyword(s):  
Abiotic Factors ◽  
Embryo Sac ◽  
Pollen Grains ◽  
Fruit Production ◽  
Pollen Grain ◽  
Egg Cell ◽  
Dispersal Mechanism ◽  
Haploid Male ◽  
Sterile Pollen ◽  
Pollen Formation

Abstract Pollination of flowers is the transfer of pollen grains (haploid male spores) from the anther (part of the androecium) to the stigma (part of the gynoecium) by biotic or abiotic factors (Sliwinska and Bewley, 2014). For seed and fruit production of agricultural crops the main pollinating agents are wind and insects (George, 2011). After a pollen grain is transferred to a receptive stigma, it absorbs water from the stigma surface and germinates. A pollen tube then grows down into the stigma, through the gynoecium and through the apical micropyle; from there it grows into an ovule in the ovary and double fertilisation then takes place. Two sperm are released into the embryo sac; one fertilises the ovule to produce a diploid zygote, and the other joins with two polar nuclei in the ovule to produce a triploid nucleus that will then develop into the nutrient-rich endosperm (Willmer, 2011). Pollen grain diameter is usually in the range 20-70 μm, and the surface structure and morphology varies considerably between plant species and dispersal mechanism (Wiltshire, 2010). Air temperature can have an effect on pollen formation and viability, with high temperatures potentially leading to sterile pollen (Bosland and Votava, 2012). Irradiated pollen grains are still able to germinate and produce pollen tubes that reach the ovule (Germana, 2012). Although they are unable to fertilise the egg cell, this process induces parthenogenesis and has been widely used to produce haploid fruits (Germana, 2012).

scholarly journals Evaluation of Arachis hypogaea × A. cardenasii Interspecific Lines for Resistance to Insect Pests1

1997 ◽  
Vol 24 (2) ◽  
pp. 89-96 ◽  
Author(s):  
R. E. Lynch ◽  
H. T. Stalker
Keyword(s):  
Arachis Hypogaea ◽  
Interspecific Cross ◽  
Fall Armyworm ◽  
Corn Earworm ◽  
Potato Leafhopper ◽  
Laboratory Evaluation ◽  
Corn Rootworm ◽  
Velvetbean Caterpillar ◽  
Southern Corn Rootworm ◽  
Moderate Resistance

Abstract Fourteen lines from the interspecific cross Arachis hypogaea X A. cardenasii were evaluated in the field and seven lines from this cross were evaluated in the laboratory for resistance to insect damage. Laboratory evaluation of interspecific lines against major defoliators of peanut showed variable levels of resistance to the corn earworm, no resistance to the fall armyworm, and moderate resistance to the velvetbean caterpillar as noted by a reduced host suitability index in line IC 2–5. Damage ratings to plants in the field indicated no resistance in the interspecific lines to the tobacco thrips. However, a high level of resistance to the southern corn rootworm was observed in most of the lines. Resistance to the potato leafhopper was indicated by reduced damage ratings for all interspecific lines relative to damage on cv. Florunner. Resistance ratings for the potato leafhopper were highest in lines GP-NC WS 7 and IC 1–19 and was evident even under severe potato leafhopper pressure. The levels of resistance to the southern corn rootworm and potato leafhopper should prove useful in a breeding program to introgress resistance to these insects into elite cultivars.

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