پیوندهای مفید
اخبار و اعلانات
آمار
| تعداد نشریات | 158 |
| تعداد شماره‌ها | 6,229 |
| تعداد مقالات | 67,747 |
| تعداد مشاهده مقاله | 115,089,334 |
| تعداد دریافت فایل اصل مقاله | 89,836,709 |
مدل‌سازی مراحل نمو یک رقم گلرنگ بهاره، با استفاده از درجه حرارت و طول روز | ||
| پژوهش های جغرافیای طبیعی | ||
| مقاله 2، دوره 42، شماره 72 - شماره پیاپی 320631، آذر 1389 اصل مقاله (566.22 K) | ||
| نویسندگان | ||
| جواد خوشحال؛ طلعت یساری؛ | ||
| چکیده | ||
| برای ارزیابی تأثیر‌پذیری طول مراحل مختلف نمو گلرنگ رقم اراک، از تغییرات طول روز و دما و مدل‌سازی سرعت نمو در دوره‌های مختلف نمو، آزمایش‌هایی با بهره‌گیری از تاریخ‌های مختلف کاشت طی سال‌های 86-1385 و 87-1386 در مزرعه تحقیقات کشاورزی کبوترآباد اصفهان انجام گردید. برای تخمین سرعت نمو طی هر مرحله، عکس طول هر مرحله به عنوان متغیر تابع و متغیرهای حرارتی، طول روز و حاصل‌ضرب متغیرهای حرارتی با متغیرهای طول روز به عنوان متغیر مستقل در رگرسیون مرحلهای مورد استفاده قرار گرفتند. مرحلهای از رگرسیون به عنوان مدل مناسب انتخاب گردید که ضریب رگرسیون و ضریب تشخیص آخرین جزء آن حداقل در سطح احتمال 10 درصد معنی‌دار باشد و حداکثر ضریب تشخیص کل را داشته باشد. تعداد روز از کاشت تا سبز شدن، سبز شدن تا رویت طبق، سبز شدن تا رسیدگی و گل‌دهی تا رسیدگی از تاریخ‌های کاشت تأثیر پذیرفت. با افزایش دما، طول مراحل نمو کاهش یافت. طول دوره سبز شدن تا رؤیت طبق بیشترین تأثیر را از طول روز پذیرفت و با افزایش آن کاهش یافت. درجه حرارت حداقل تنها متغیری بود که وارد مدل شد و به تنهایی حدود 76 درصد تغییرات سرعت سبز شدن رقم اراک را توضیح داد. حدود 84 درصد تغییرات سرعت نمو در طول دوران سبز شدن تا رویت طبق به‌وسیله حاصل‌ضرب درجه حرارت حداکثر در طول روز، توجیه گردید. بخش عمده واریانس سرعت نمو این رقم طی دوران سبز شدن تا رسیدگی به‌وسیله حاصل‌ضرب مربع میانگین حرارت در مربع طول روز و به میزان حدود 66 درصد توضیح داده شد. حاصل‌ضرب میانگین دما در طول روز، توان چهارم، دوم و اول درجه حرارت حداقل متغیرهای بعدی بودند که وارد مدل شدند و روی هم حدود 80 درصد تغییرات سرعت این دوره را بیان کردند. توان چهارم درجه حرارت حداقل تنها متغیری بود که سرعت نمو مرحله گل‌دهی تا رسیدگی را به میزان حدود 55 درصد توضیح داد. | ||
| کلیدواژه‌ها | ||
| دما؛ طول روز؛ گلرنگ؛ مدل‌سازی؛ مراحل نمو | ||
| عنوان مقاله [English] | ||
| Modeling of Various Developmental Stages in One Spring Safflower by Temperature and Day Length | ||
| نویسندگان [English] | ||
| J Khoshhal؛ T Yasari؛ | ||
| چکیده [English] | ||
| Introduction Safflower is an annual, broad leaf oil seed crop of the family compositae adapted chiefly to dry land. Safflower is originally a cold season and long day crop. It is believed to have originated in southern Asia and is known to have been cultivated in China, India, Iran and Egypt almost from prehistoric times. During the middle ages, it was cultivated in Italy, France and Spain and soon after discovery of America, the Spanish took it to Mexico and then to Venezuela and Colombia. Safflower was originally grown as the flowers that were used in making red and yellow dyes for clothing and food preparation. Today also safflower can be cultivated for oil, foots medicinal purpose and cosmetic products. The planted area has reached 795118 ha and resulted in 731425 tons of production in the world during 2004. Planted area in Iran is about 6000 ha with 1 ton seed yield per ha. The highest planted areas in Iran belong to Isfahan, Khorasan and Yazd provinces respectively. Plant development can be defined as a programmed qualitative change in the plant form, which leads plant to maturity, and researchers call it the phases of development or phenology. Plant development is different from plant growth, because plant growth is the result of photosynthesis process during which dry matter accumulates. Water, nitrogen and photosynthetic matters affect growth and development. Under irrigated conditions, all factors except climatic elements can be controled. Thus, only the climatic elements can change the growth and the development of plants and in this case, temperature and day length have the main role. Materials and Methods Field experiments were conducted in 2006-2007 and 2007-2008 at the Kaboutar Abad Agricultural Research Station, to model the response of Arak variety to day length and temperature changes in different planting dates. Developmental rate of each stage was estimated using the inverse of developmental duration as the dependent variable and various temperature variables derived from daily maximum (Tmax), minimum (Tmin) and mean (Tmean), day length (DL) and the combination of these variables as the independent variables in stepwise regression models. A step of the regression was considered appropriate if the highest R2 was accompanied by the significant (R<0.1) regression coefficient and partial coefficient of determination. Results and Discussion The number of days from planting to emergence, emergence to head visible, emergence to ripening and flowering to ripening were affected by planting dates. Developmental stages reduced as temperature increased. Day length had the most effect on emergence to head visible period and reduced as day length increased. Tmin was the only variable which entered the regression model and explained about 76% of variation in the rate of emergence of Arak. About 84% of variation in the rate of emergence to head visible was explained by Tmax × DL. Most of the variation (about 66%) in the rate of emergence to ripening period was explained by T2mean × DL2, Tmean × DL, T4min, T2min, and Tmin were the other variables that entered the model and reached the precision of the model by about 80%. T4min was the only variable that entered the regression model and explained 55 % of variation in rate of flowering to ripening period.B ased on the ration of absolute value of maximum deviation from the regression line , to actual period of developmental stages (expressed in percentages), long developmental stages were well estimated that indicate the efficiency of the calculated models. Conclusion The results of this study indicate that the contribution of temperature and day length to various stages of development do not have the same differences in physiological nature of developmental stages and differences in the responses of developmental stages to climatic, edaphic and agronomic factors and the interactions of these factors with each other and with plant genotypes may be responsible for these reactions. Thus, a separate model may be needed for each cultivar and each developmental stage. Dividing the country to homogenous groups, with respect to temperature and day length, may increase the accuracy of estimating models. This requires availability of sufficient phonological information from various climatic zones. | ||
| کلیدواژه‌ها [English] | ||
| Day length, Developmental Stages, modeling, Safflower, temperature | ||
|
آمار تعداد مشاهده مقاله: 2,639 تعداد دریافت فایل اصل مقاله: 2,779 |
||