Tayebeh Alsadat Cheraghi Takht Choobi; Seyed Amir Moosavi; Ahmad zare; Ahmad KoochekZade; ghasem parmoon
Abstract
In order to determine the cardinal temperature of decayed sugarcane seeds, this study was carried out factorially in a completely randomized design with three replications in Khuzestan University of Agriculture and Natural Resources. The first factor was aging at 5 levels (0, 24, 48, 72 and 96 hours ...
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In order to determine the cardinal temperature of decayed sugarcane seeds, this study was carried out factorially in a completely randomized design with three replications in Khuzestan University of Agriculture and Natural Resources. The first factor was aging at 5 levels (0, 24, 48, 72 and 96 hours of decline) and germination temperatures at 7 levels (5, 10, 15, 20, 25, 30, 35 and 40 ° C). The results showed that the percentage and speed of germination were affected by the interaction of temperature in the decay so that their highest value was in the temperature range of 20 to 25 ° C and the decay in addition to reducing their amount increased the range of changes of this plant at different temperatures. The highest germination percentage was observed at 20 ° C in undeveloped seeds and 15 to 20 ° C at 24 and 48 h. Estimation of different non-linear models on germination rate also showed that among the evaluated models, the better toothed model was the model for germination of sugarcane seeds at different levels of decay. The germination basal temperature of sugarcane was estimated to be 1 ° C in non-degradable conditions, which increased to 1.8 ° C in 24 hours of decline and decreased again in higher degradations. The optimum germination temperature of this plant was between 20 to 32 at no aging conditions.
Tayebeh Alsadat Cheraghi Takht Choobi; Seyed Amir Moosavi; ahmad zare; Ahmad KoochekZade; ghasem parmoon
Abstract
The effects of accelerated aging treatment on seed germination of Echinops was quantified using nonlinear models using Sigmoid, Segmented, Gompertz and Richards models and hydrotime model in Weibull, Normal and Gombel distribution functions. Experimental factors were seed aging for (0, 24, 48, 72 and ...
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The effects of accelerated aging treatment on seed germination of Echinops was quantified using nonlinear models using Sigmoid, Segmented, Gompertz and Richards models and hydrotime model in Weibull, Normal and Gombel distribution functions. Experimental factors were seed aging for (0, 24, 48, 72 and 96 hour) at relative humidity (RH)=100%, temperature (T) =40 oC and seven osmotic potential (0, -0.2, -0.4, -0.6, -0.8, -1, -1.2 MPa). Results of experiment revealed that interaction effect of aging and osmotic stress on seed germination and germination rate of Echinopsis was significant. Seed germination parameters of Echinops were increase by aging treatment up to 72 h but it was declined at aging treatment of 96 h. Seed germination and germination rate were increased by aging treatment till 72 h but at 96 h, both were declined. Gompertz exhibited the best fit for no aged, 24 h and 48 h while sigmoid function was provided the best fit for aging at 72 and 96 h. Among all studied distribution function, it was revealed that normal distribution was the most effective one thus base potential (ψb) and hydrotime constant (θH) were -0.68 MPa and 6 MPa hour, respectively. However, after 96 h of aging treatment ψb and θH were estimated 0.731 MPa and 19.3 MPa hour, respectively. It can be concluded that freshly harvested Echinops exhibited some levels of seed dormancy which was alleviated at mild to moderate aging conditions, but after 72 h, deteriorative mechanism led to damaging effects and declined seed germination quality.
