scholarly journals The Embryo Characteristics and Genes Expression Analysis Involved in Apomixis of Wild Germplasm Materials of Kentucky Bluegrass in Gansu Province of China

2021 ◽  
Author(s):  
Jinqing Zhang ◽  
Huiling Ma
Keyword(s):  
Sexual Reproduction ◽  
Seed Production ◽  
Expression Analysis ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Gansu Province ◽  
Hybrid Breeding ◽  
Transcriptional Level ◽  
Wild Germplasm ◽  
Stability And Consistency

Abstract Background: Apomixis is mainly used to maintain the heterosis, stability, and consistency of crops. Its main advantage is to reduce the costs of seed production and shorten the breeding process. In the field of hybrid breeding, apomixis has been referred to as the "asexual revolution" and has realized a new green revolution.Apomixis is mainly used to maintain the heterosis, stability, and consistency of crops. Its main advantage is to reduce the costs of seed production and shorten the breeding process. In the field of hybrid breeding, apomixis has been referred to as the "asexual revolution" and has realized a new green revolution. Kentucky bluegrass (Poa pratensis) is a natural apomictic species that mainly exhibits facultative apospory. Its main feature is that the somatic nucellar cells bypass meiosis and double fertilization to form unreduced embryos, and the development of the endosperm requires pseudogamy. Although apomixis is of great significance in breeding, the genetic control of apomixis remains unclear. Therefore, we report the results of a global gene expression analysis of wild germplasm materials of Kentucky bluegrass spikelets in Gansu province of China, exhibiting significant differences in apomictic rates to identify the genes, biological processes, and molecular functions related to apomixis.Result: At four reproductive periods, there were 5400 differentially expressed genes (DEGs) between the two genotypes, including 2476 downregulated and 2823 upregulated genes. Further analysis of the gene functions, pathways, expression patterns, networks, and transcription factors (TFs) showed that the occurrence of apomixis in Kentucky bluegrass was related to changes in the time- and space-related expression of genes associated with sexual reproduction, which led to disordered sexual reproduction and thus the production of offspring by apomixis. Conclusion: At the transcriptional level, the genesis and development of apomixis was regulated by TFs. It also involved the coexpression of many genes associated with disordered meiosis, hormone signal transduction, embryonic development, stress response pathways, and epigenetics. We also verified these 16 DEGs by real-time quantitative PCR. The expression results were basically consistent with the transcriptome expression profile, indicating that the transcriptome data were reliable. The results of this study may provide a theoretical basis for revealing the mechanism of occurrence and development of apomixis in Kentucky bluegrass.

Residue management increases seed yield of three turfgrass species on the Canadian prairies

2002 ◽  
Vol 82 (4) ◽  
pp. 687-692 ◽  
Author(s):  
B. D. Gossen ◽  
J. J. Soroka ◽  
H. G. Najda
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Poa Pratensis ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Residue Management ◽  
Row Spacing ◽  
Seeding Rate ◽  
Canadian Prairies ◽  
The Impact

Little information is available on the management of turfgrass species for seed production in the Canadian prairies. The objective of these studies was to assess the impact of residue management and row spacing on seed yield under irrigation. A factorial experiment was seeded at Saskatoon, SK, in 1993 to assess the impact of burning or scalping (very close mowing with residue removal) vs. mowing, and 20- vs. 40-cm row spacing on seed yield of Kentucky bluegrass (KBG) (Poa pratensis), creeping red fescue (CRF) (Festuca rubra subsp. rubra) and creeping bentgrass (CBG) (Agrostis palustris). Also, a residue management trial on KBG was seeded at Brooks, AB, in 1993. At Saskatoon, yield was higher at 20-cm spacing across all three species in 1994, but spacing had no impact on winter survival, stand density, tiller growth or yield in subsequent years. Burning and scalping consistently resulted in earlier spring green-up, a higher proportion of fertile tillers, and higher seed yield than mowing. Even with residue management, yield declined after one harvest in CBG and CRF, and after two harvests in KBG. At Brooks, residue management had a similar impact on yield of KBG. A second trial at Brooks examined the impact of row spacing (20, 40, 60 cm) and seeding rate (0.5 to 6 kg seed ha-1) on KBG. Seed yield was highest at 40-cm spacings in 1994, at 60 cm in 1995, and at 40 to 60 cm in 1996. Seeding rate did not have a consistent effect on yield. We conclude that a combination of residue management and 20- to 40-cm spacings provide the highest, most consistent seed yields for these turfgrass species in this region. Key words: Burning, clipping, turfgrass, seed production, row spacing, Poa, Festuca, Agrostis

INFLUENCE OF NITROGEN FERTILIZATION AND MECHANICAL STUBBLE REMOVAL ON SEED PRODUCTION OF KENTUCKY BLUEGRASS IN MANITOBA

1989 ◽  
Vol 69 (3) ◽  
pp. 939-943 ◽  
Author(s):  
D. J. THOMPSON ◽  
K. W. CLARK
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Nitrogen Fertilization ◽  
Field Experiments ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
N Fertilization ◽  
Shoot Height ◽  
Straw Yield ◽  
Panicle Weight

Three field experiments were performed to determine the effects of fall nitrogen fertilization and post-harvest mechanical stubble removal (to 2.5 cm) on seed yield in Kentucky bluegrass (Poa pratensis L. ’Nugget’). In all experiments, N fertilization and stubble removal increased seed yield. Increases were greater in a 3-yr-old than in a 5-yr-old stand. Nitrogen fertilization increased panicle density, panicle weight, shoot height and straw yield. Stubble removal increased panicle density, reduced panicle weight, shoot height, and straw yield and increased harvest index.Key words: Nitrogen, stubble removal, seed, Kentucky bluegrass

Silvertop in perennial grass seed production: Effects of type and timing of biotic stresses

2021 ◽  
Author(s):  
Julie Soroka ◽  
Bruce D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Perennial Grass ◽  
Kentucky Bluegrass ◽  
Development Stage ◽  
Perennial Grasses ◽  
Grass Species ◽  
Biotic Stresses ◽  
Seed Harvest ◽  
Bromus Riparius

Seed production of perennial grasses is an important industry in Canada, but many fields exhibit high proportions of sterile heads with characteristic symptoms in a condition known as silvertop. In a 3-yr field study, biotic stress treatments were applied to caged plots of Kentucky bluegrass (<i>Poa pratensis</i>) and meadow bromegrass (<i>Bromus riparius</i>) to assess their effects on silvertop incidence. Treatments were: 1) control, 2) addition of grass-feeding insects, primarily grass plant bugs (Miridae), 3) inoculation with <i>Fusarium poae</i> spores, 4) both insects and spores, and in one year, 5) mechanical piercing of seed heads above the last node. Additionally, cores of the two grass species were potted and removed from the field in spring in each of 2 years. After 2-, 4-, and 6-wk intervals in a cold room at 4° C to stagger plant development stage, the five treatments were applied to caged plants of both grasses, which were maintained in a greenhouse until seed harvest. In both studies, the numbers of healthy seed heads, percentage of heads with silvertop, and seed weights were determined. In the field, stress treatments infrequently and inconsistently affected silvertop levels. Regression showed that the relationship between silvertop and seed yield, although significant, explained little of the variability in yield. Silvertop developed in all treatments in the greenhouse; treatments had no effect on silvertop levels, which were highest in plants treated at the R1 (boot) growth stage. This suggests that the boot stage of the two grass species is most vulnerable to silvertop occurrence.

Phytophagous arthropods and silvertop levels associated with post-harvest residue treatments in three turfgrass species grown for seed

2005 ◽  
Vol 85 (1) ◽  
pp. 213-224 ◽  
Author(s):  
J. J. Soroka ◽  
B. D. Gossen
Keyword(s):  
Seed Production ◽  
Poa Pratensis ◽  
Creeping Bentgrass ◽  
Kentucky Bluegrass ◽  
Residue Management ◽  
Grass Species ◽  
Festuca Rubra ◽  
Agrostis Palustris ◽  
Red Fescue ◽  
The Impact

Silvertop, which is characterized by whitish, completely sterile seed heads produced on green tillers, is a common symptom in many perennial grasses. A 3-yr study of creeping bentgrass (Agrostis palustris), Kentucky bluegrass (Poa pratensis) and creeping red fescue (Festuca rubra subsp. rubra) grown for seed production was conducted at Saskatoon, Saskatchewan, to investigate the cause(s) of silvertop, the impact of residue management strategies on silvertop incidence, and the impact of silvertop on seed yield. Three residue management practices were applied in the fall of the first harvest year and again the next fall, as follows: (i) burned after harvest; (ii) clipped to 1–2 cm in height and the residue removed; or (iii) mowed to 20 cm and the residue retained. Arthropods in each plot were collected weekly from May until July by sweep sampling, counted, and identified to family level or lower, and the incidence of seed heads with and without silvertop were assessed. The majority of arthropods were thrips, leafhoppers, plant bugs, mites, or grass-dwelling flies. Grass species and residue treatment strongly affected the number of reproductive tillers and levels of silvertop. Levels of silvertop were lowest in creeping bentgrass in all 3 yr of the study, while they were similar for Kentucky bluegrass and creeping red fescue. Mown plots had fewer reproductive tillers, fewer heathy seed heads, and higher levels of silvertop than burned or clipped plots. However, arthropod species composition was generally similar across grass species and residue treatments. This indicates that a specific arthropod taxon may not be a critical factor in silvertop expression. The relationship between the number and composition of arthropods found and incidence of silvertop is discussed. Key words: Festuca rubra subsp. rubra, Poa pratensis, Agrostis palustris, seed production, arthropods, silvertop

Effect of Picloram on Production and Quality of Seed in Several Grasses

Weed Science ◽  
1970 ◽  
Vol 18 (1) ◽  
pp. 171-173 ◽  
Author(s):  
William O. Lee
Keyword(s):  
Seed Production ◽  
Seed Quality ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Italian Ryegrass ◽  
Grass Species ◽  
Red Fescue ◽  
Agrostis Tenuis ◽  
Untreated Check

Twelve field trials were conducted in western Oregon during 1963 to 1966 to evaluate the effect of 4-amino-3,5,6-trichloropicolinic acid (picloram) on the seed production and seed quality of eight grass species. Seed production of creeping bentgrass (Agrostics palustris Huds., vars. Penncross and Seaside), Colonial bentgrass (Agrostis tenuis Sibth., var. Highland), perennial ryegrass (Lolium perenne L., var. Linn), Italian ryegrass (Lolium multiflorum Lam., var. Gulf), and tall fescue (Festuca arundinacea Schreb., var. Alta) treated with picloram was not statistically different from the untreated check. Seed production of Colonial bentgrass (Agrostis tenuis Sibth., var. Astoria) was reduced by picloram at rates of 1.0 and 1.5 lb/A. Seed production of Kentucky bluegrass (Poa pratensis L., var. Newport) was not statistically different from the untreated check when picloram was applied in October but was significantly lower than the check following some March treatments. Seed production of orchardgrass (Dactylis glomerata L., var. Potomac) and creeping red fescue (Festuca rubra L., var. Pennlawn) was reduced by most picloram treatments made either in October or March. Germination of the creeping red fescue seed was significantly reduced when picloram was applied at 2 lb/A in March. None of the treatments affected seedling development.

Control of Volunteer Wheat (Triticum aestivum) in Fall-Planted Perennial Ryegrass (Lolium perennne) with Ethofumesate

Weed Science ◽  
1980 ◽  
Vol 28 (3) ◽  
pp. 292-294 ◽  
Author(s):  
W. O. Lee
Keyword(s):  
Triticum Aestivum ◽  
Seed Production ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Field Experiments ◽  
Poa Pratensis ◽  
Lolium Multiflorum ◽  
Kentucky Bluegrass ◽  
Italian Ryegrass ◽  
The One

Ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] was evaluated in field experiments at rates from 0.6 to 4.5 kg/ha for control of volunteer wheat (Triticum aestivumL. ‘Hyslop’, ‘Stephens’) in fall-planted perennial ryegrass (Lolium perenneL. ‘Cropper’, ‘Pelo’, ‘Pennfine’, ‘Omega’). Ethofumesate applied at 1.7 kg/ha or more in mid-November to wheat in the one-to three-leaf stage eliminated the wheat. Wheat was not eliminated when ethofumesate was applied preemergence soon after planting or when applied at the end of November to wheat in the four-leaf to four-tiller stage. In four experiments in which wheat was present, ethofumesate significantly increased perennial ryegrass seed production. In one experiment in which wheat was not present, ethofumesate did not affect perennial ryegrass seed production. Ethofumesate applied in the fall at rates to 4.5 kg/ha to newly-seeded perennial ryegrass or to well-established bentgrass (Agrostis tenuisSibth. ‘Highland’), Kentucky bluegrass (Poa pratensisL. ‘Newport’), and Italian ryegrass (Lolium multiflorumLam.) did not adversely affect germination of the following seed crop.

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