EFFECT OF SEED INFESTATION AND FLOWER BUD INOCULATION ON SYSTEMIC INFECTION OF TURNIP RAPE BY ALBUGO CANDIDA

1980 ◽  
Vol 60 (1) ◽  
pp. 267-271 ◽  
Author(s):  
P. R. VERMA ◽  
G. A. PETRIE

Oospores of (Albugo candida race 7 mixed with seeds of turnip rape (Brassica campestris L. ’Torch’) prior to sowing resulted in a significant increase over the control in both locally (foliar) and systemically-infected plants in field plots, demonstrating the potential importance of seed infestation in initiating the disease. In growth room studies, inoculation of flower buds with zoospores resulted in a 10-fold increase, over cotyledon and leaf inoculations, in the number of stagheads on turnip rape. Over 55% of the flower-bud-inoculated plants produced stagheads. Results suggest that flower bud infection is probably a major source of systemic infection of individual branches. Stagheads may also result from systemic infection beginning at the seedling stage.

1979 ◽  
Vol 59 (2) ◽  
pp. 423-427 ◽  
Author(s):  
J. DUECK ◽  
J. R. STONE

Two applications of the protectant fungicides, Bravo, Manzate 200 and DPX 164 reduced foliar infection of turnip rape (Brassica campestris) by Albugo Candida. However, the fungicides had no apparent effect on staghead formation, the systemic phase of the disease. The acylalanine fungicides CGA 29212 and CGA 48988 showed excellent eradicant activity against foliar infection in growth room tests. In a field test, CGA 29212 significantly reduced the number of stagheads. CGA 38140 showed no activity against A. Candida on turnip rape.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jian Wang ◽  
Yitao Yang ◽  
Lei Zhang ◽  
Shaoxing Wang ◽  
Lingyun Yuan ◽  
...  

Abstract Background The discovery of male sterile materials is of great significance for the development of plant fertility research. Wucai (Brassica campestris L. ssp. chinensis var. rosularis Tsen) is a variety of non-heading Chinese cabbage. There are few studies on the male sterility of wucai, and the mechanism of male sterility is not clear. In this study, the male sterile mutant MS7–2 and the wild-type fertile plant MF7–2 were studied. Results Phenotypic characteristics and cytological analysis showed that MS7–2 abortion occurred at the tetrad period. The content of related sugars in the flower buds of MS7–2 was significantly lower than that of MF7–2, and a large amount of reactive oxygen species (ROS) was accumulated. Through transcriptome sequencing of MS7–2 and MF7–2 flower buds at three different developmental stages (a–c), 2865, 3847, and 4981 differentially expressed genes were identified in MS7–2 at the flower bud development stage, stage c, and stage e, respectively, compared with MF7–2. Many of these genes were enriched in carbohydrate metabolism, phenylpropanoid metabolism, and oxidative phosphorylation, and most of them were down-regulated in MS7–2. The down-regulation of genes involved in carbohydrate and secondary metabolite synthesis as well as the accumulation of ROS in MS7–2 led to pollen abortion in MS7–2. Conclusions This study helps elucidate the mechanism of anther abortion in wucai, providing a basis for further research on the molecular regulatory mechanisms of male sterility and the screening and cloning of key genes in wucai.


1982 ◽  
Vol 62 (3) ◽  
pp. 823-826 ◽  
Author(s):  
A. ALI ◽  
V. SOUZA MACHADO

In field conditions, rutabaga (Brassica napus ssp. Rapifera (Metzg.) Sinsk.) plants are biennials and require exposure to low temperature for completion of their life cycle to seed production state. When young rutabaga plants were thermoinduced (3–5 °C) for 8 wk and subsequently transferred to growth room conditions, formation of flower buds resulted in 6 wk. Flowering response was greatly enhanced if the plants were sprayed with GA3 (100 mg/L) prior to thermoinduction. Compared with untreated plants, the GA3-sprayed plants responded with flower bud formation after as little as 3 wk of cold treatment. A longer cold exposure (6–8 wk) of the GA3-sprayed plants resulted in rapid development and maturity of the inflorescence. This note emphasizes the pharmacological role of gibberellins as regulators of flowering and their usefulness to enhance seed production and plant breeding programs.


1997 ◽  
Vol 101 (3) ◽  
pp. 583-590 ◽  
Author(s):  
Na Eun Cheong ◽  
Yeon Ok Choi ◽  
Woe Yeon Kim ◽  
Sun Chang Kim ◽  
Moo Je Cho ◽  
...  

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).


2021 ◽  
Vol 22 (8) ◽  
pp. 3932
Author(s):  
Jing Cao ◽  
Qijiang Jin ◽  
Jiaying Kuang ◽  
Yanjie Wang ◽  
Yingchun Xu

The lotus produces flower buds at each node, yet most of them are aborted because of unfavorable environmental changes and the mechanism remains unclear. In this work, we proposed a potential novel pathway for ABA-mediated flower timing control in the lotus, which was explored by combining molecular, genetic, transcriptomic, biochemical, and pharmacologic approaches. We found that the aborting flower buds experienced extensive programmed cell death (PCD). The hormonal changes between the normal and aborting flower buds were dominated by abscisic acid (ABA). Seedlings treated with increasing concentrations of ABA exhibited a differential alleviating effect on flower bud abortion, with a maximal response at 80 μM. Transcriptome analysis further confirmed the changes of ABA content and the occurrence of PCD, and indicated the importance of PCD-related SNF1-related protein kinase 1 (NnSnRK1). The NnSnRK1-silenced lotus seedlings showed stronger flowering ability, with their flower:leaf ratio increased by 40%. When seedlings were treated with ABA, the expression level and protein kinase activity of NnSnRK1 significantly decreased. The phenotype of NnSnRK1-silenced seedlings could also be enhanced by ABA treatment and reversed by tungstate treatment. These results suggested that the decline of ABA content in lotus flower buds released its repression of NnSnRK1, which then initiated flower bud abortion.


1966 ◽  
Vol 46 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Walter J. Kender ◽  
Franklin P. Eggert

A field experiment using various soil management practices showed that the most effective means to increase blueberry plant spread was through the use of a surface mulch. Peat and sawdust were of equal suitability as a mulching material influencing vegetative growth, although sawdust did result in a reduction in the number of flower buds produced when compared with peat. Mulching was associated with a higher soil moisture content than non-mulched plots.Blueberry plants growing in nitrogen-treated plots had an increased flower bud number and rhizome growth in contrast with those growing in unfertilized plots. Nitrogen fertilization was of particular benefit when applied in association with surface organic mulches.Plants growing in an undisturbed soil were more vigorous than in a homogenized or tilled soil. Sawdust was found to be detrimental to the growth of lowbush blueberry plants when incorporated into a homogenized soil.


1978 ◽  
Vol 58 (2) ◽  
pp. 427-434 ◽  
Author(s):  
G. R. STRINGAM ◽  
R. K. DOWNEY

Isolation distances for turnip rape (Brassica campestris L.) were studied using the recessive genetic marker yg-7. Average contamination levels from six tests over 2 yr were 8.5, 5.8, and 3.7% at isolation distances of 46, 137, and 366 m, respectively. The 46- and 137-m distances were judged to be inadequate, and even the 366-m distance showed greater contamination levels than desirable. No significant border effects were observed and there were no detectable differences in contamination attributable to directional orientation of the isolation blocks with the contaminant source. The data suggest that the 50- and 100-m isolation requirements in Canada for Certified seed production of turnip rape be re-examined and that border removal in lieu of spatial isolation be seriously questioned.


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