Effect of Temperature and Light Regimes on Germination Behavior of Rapeseed (Brassica napus) Cultivars

AbstractSeed germination of two local Greek endemics was studied (Erysimum naxense, Erysimum krendlii). Seed viability was determined by using the tetrazolium method and germination was studied in synchronized cycles of five and four alternating temperatures [10/5 (for E. naxense only) and 15/10, 20/15, 25/20, and 30/25°C for both species, in cycles of 16 h day/8 h night], and in five light regimes (red, blue, green, white, and dark). Germination of E. naxense and E. krendlii seeds was determined daily for six and five weeks, respectively, with the data analyzed as viability adjusted accumulative seed germination at the end of each week. E. naxense’s seed viability was higher (90%) than that of E. krendlii (64%); seed germination (%) of both increased at low alternating temperatures (10/5°C, 15/10°C, 20/15°C). Germination of E. naxense seeds at low temperatures was light-independent, whereas at high temperatures it was increased with red light. Germination of E. krendlii seeds was inconsistently affected by light at the temperatures studied. Percentages of seed germination of both species were higher in experimental conditions similar to the ones of their natural habitats during autumn and/or spring (facilitated with Geographic Information Systems). These conclusions provide guidelines for species-specific propagation protocols and ex situ conservation.

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The Effect of Temperature on the Hypersensitive Response (HR) in the Brassica napus–Leptosphaeria maculans Pathosystem

Plants ◽

10.3390/plants10050843 ◽

2021 ◽

Vol 10 (5) ◽

pp. 843

Author(s):

Cunchun Yang ◽

Zhongwei Zou ◽

Wannakuwattewaduge Gerard Dilantha Fernando

Keyword(s):

Brassica Napus ◽

Leptosphaeria Maculans ◽

The Other ◽

Effect Of Temperature ◽

Marker Genes ◽

Temperature Sensitive ◽

Temperature Changes ◽

Pathogenesis Related ◽

Two Temperature ◽

Incompatible Interactions

Temperature is considered one of the crucial environmental elements in plant pathological interactions, and previous studies have indicated that there is a relationship between temperature change and host–pathogen interactions. The objective of this research is to investigate the link between temperature and the incompatible interactions of the host and pathogen. In this study, two Leptosphaeria maculans isolates (HCRT75 8-1 and HCRT77 7-2) and two Brassica napus genotypes (Surpass400 and 01-23-2-1) were selected. The selected B. napus genotypes displayed intermediate and resistant phenotypes. The inoculated seedlings were tested under three temperature conditions: 16 °C/10 °C, 22 °C/16 °C and 28 °C/22 °C (day/night: 16 h/8 h). Lesion measurements demonstrated that the necrotic lesions from the 28 °C/22 °C treatment were enlarged compared with the other two temperature treatments (i.e., 16 °C/10 °C and 22 °C/16 °C). The results of expression analysis indicated that the three temperature treatments displayed distinct differences in two marker genes (PATHOGENESIS–RELATED (PR) 1 and 2) for plant defense and one temperature-sensitive gene BONZAI 1 (BON1). Additionally, seven dpi at 22 °C/16 °C appeared to be the optimal pre-condition for the induction of PR1 and 2. These findings suggest that B. napus responds to temperature changes when infected with L. maculans.

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Evaluation of reproductive success and conservation strategies for Senecio coincyi (Asteraceae), a narrow and threatened species

Australian Journal of Botany ◽

10.1071/bt12109 ◽

2012 ◽

Vol 60 (6) ◽

pp. 517 ◽

Cited By ~ 3

Author(s):

F. Martínez-García ◽

S. Guerrero-García ◽

F. Pérez-García

Keyword(s):

Reproductive Success ◽

Intraspecific Variability ◽

Effect Of Temperature ◽

Conservation Strategies ◽

Individual Plant ◽

Endemic Plant ◽

Light Regimes ◽

Area Of Occupancy ◽

Germination Behaviour ◽

Western Spain

Senecio coincyi is a threatened endemic plant of central western Spain, with a very narrow extent of occurrence. The reproductive success and germination behaviour of this species were studied. The area of occupancy, habitat types and size of 13 known subpopulations of S. coincyi were evaluated. The number of individuals that form all these subpopulations was counted. In addition, the number of flowers and cypselas per fruit head and the number of fruit heads per individual plant were recorded in a subset of subpopulations. Germination tests were carried out to evaluate the effect of temperature and light regimes on, and possible intraspecific variation in, cypsela germination. Cypselas reached very high germination percentages (90–100%) from 15°C to 30°C. However, the germination decreased (19%) at 10°C. The light conditions assayed (16-h light photoperiod and complete darkness) did not significantly affect cypsela germination. In general, there was no intraspecific variability in germination patterns of S. coincyi cypselas. Livestock is the most important factor that can be a threat for this species. S. coincyi showed high reproductive success and, therefore, its conservation problems are not due to agents related to its reproduction, but rather to other factors such as alteration of its habitat caused by the presence of livestock.

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Effect of temperature on the life cycle of Heterodera schachtii infecting oilseed rape (Brassica napus L.)

Nematology ◽

10.1163/156854112x631935 ◽

2012 ◽

Vol 14 (7) ◽

pp. 855-867 ◽

Cited By ~ 9

Author(s):

Stephen Kakaire ◽

Ivan G. Grove ◽

Patrick P.J. Haydock

Keyword(s):

Life Cycle ◽

Brassica Napus ◽

Oilseed Rape ◽

Second Generation ◽

Cultivar Differences ◽

Effect Of Temperature ◽

Optimum Temperature ◽

Degree Days ◽

Temperature Range ◽

The Uk

Oilseed rape (OSR; Brassica napus L.) is a crop of increasing world importance and suffers yield loss when infected with Heterodera schachtii. The in vitro hatch, in planta root invasion and development of a field population of H. schachtii were investigated in six thermostatically-controlled water baths at temperatures of 5.0, 10.1, 20.5, 27.8, 32.2 and 37.5°C in a glasshouse. The UK winter OSR cvs Flash and Castille were used. Temperature was shown to have a major influence on the development of H. schachtii in OSR. The highest cumulative percentage hatch of second-stage juveniles (J2) observed over an 8-week incubation period occurred between 20.5 and 27.8°C in leachates of both OSR cultivars, indicating that this is the optimum temperature range for hatching of this population. Cumulative hatch was lowest at 37.5 and 5.0°C. Root invasion was inhibited at 5.0 and 37.5°C, whilst the highest number of J2 invaded the roots between 20.5 and 32.2°C, indicating that this is the optimum temperature range for root invasion. The life cycle took between 21 days at 20.5°C and 42 days at 5.0°C from the inoculated J2 to the J2 of the second generation, with the associated accumulated heat units (AHU) of 424 and 203 degree-days with a base temperature (Tb) of 5.0°C. The optimum temperature range (To) for development was between 20.5 and 27.8°C and the maximum (Tm) was 37.5°C. As temperature increased, the AHU required to complete the life cycle increased from 203 degree-days at 5.0°C to 1406 at 37.5°C. Leachates from both OSR cultivars stimulated more J2 to hatch than the distilled water controls. No significant cultivar differences were observed for J2 hatching, root invasion and duration of the life cycle at the different temperatures but significantly more cysts of the second generation (g root)−1 were observed in cv. Flash than cv. Castille at 27.8 and 32.2°C, suggesting that the latter cultivar is a poorer host of H. schachtii than cv. Flash. This is the first report of the effect of temperature on H. schachtii development on current winter OSR cultivars in the UK and provides insight into the potential effects of climate change on the nematode-host interaction.

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TEMPERATURE, LIGHT, AND DESICCATION TOLERANCE IN SEED GERMINATION OF Mauritia flexuosa L.F.

Revista Árvore ◽

10.1590/1806-90882018000300005 ◽

2018 ◽

Vol 42 (3) ◽

Author(s):

Lívia Caroline Praseres de Almeida ◽

Kathia Fernandes Lopes Pivetta ◽

Renata Gimenes ◽

Gustavo de Nobrega Romani ◽

Marcos Vieira Ferraz ◽

...

Keyword(s):

Seed Germination ◽

Desiccation Tolerance ◽

Polynomial Regression ◽

Germination Rate ◽

Ornamental Plants ◽

Effect Of Temperature ◽

Randomized Experiments ◽

Light Regimes ◽

Palm Trees ◽

Mauritia Flexuosa

ABSTRACT Palm trees are widely used as ornamental plants, besides its sustainability and industry aspects. These plants are commercially propagated via seeds. Due to its importance and the need for seed germination information, this study aimed to verify the effect of temperature, light regimes, and desiccation tolerance on germination of Mauritia flexuosa L.f. For that, two completely randomized experiments were carried out. The first consisted of treatments arranged in a 6 x 2 factorial scheme, testing six temperatures (20, 25, 30, 35, 20-30, and 25-35 ºC) and light presence and absence. The second comprised five seed water contents (51, 48, 45, 30, and 26%) for desiccation tolerance evaluations. Water content measurements were made every three days, from a sample lot maintained at room temperature. In both trials, each treatment was composed of four replicates with 25 seeds per plot. Germination rate (GR) and germination speed index (GSI) were calculated, and the data were analyzed by analysis of variance (ANOVA). Temperature and light means were compared by the Tukey’s test (p < 0.05), and the desiccation ones by a polynomial regression. The highest GR was observed at 20-30 ºC, regardless of light presence. Moreover, M. flexuosa seeds were sensitive to desiccation.

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