كليدواژه :
اكوتيپ , سرعت رشد محصول , عملكرد , فاصله روي رديف , هدايت روزنه‌اي
چكيده فارسي :
تعیین تراكم بهینه یكی از عوامل مهم برای به‌دست آوردن حداكثر عملكرد در هر شرایط اقلیمی و هر رقم گیاهی می‌باشد. حنا با نام علمیLowsonia inermis L. گیاهی چند ساله است كه از لحاظ دارا بودن خواص دارویی و كاربردهای صنعتی از ارزش بالایی برخوردار است. این تحقیق به‌منظور بررسی واكنش‌های زراعی-فیزیولوژیك اكوتیپ‌های مختلف گیاه حنا (شهداد، بم و رودبار) به تراكم‌های مختلف كاشت (25، 33، 50 و 100 بوته در مترمربع) در شرایط آب و هوایی كرمان به‌صورت فاكتوریل و در قالب طرح پایه بلوك‌های كامل تصادفی با سه تكرار انجام شد. نتایج نشان داد اكوتیپ‌های مورد بررسی از لحاظ شاخص‌های سرعت رشد محصول، سرعت رشد نسبی و میزان هدایت روزنه‌ای تفاوت معنی‌داری با یكدیگر داشتند و بیشترین میانگین این صفات مربوط به اكوتیپ شهداد بود. بین تراكم‌های مورد بررسی نیز از لحاظ اكثر صفات اندازه‌گیری شده اختلاف معنی‌داری از لحاظ آماری مشاهده شد. نتایج مقایسه میانگین حاكی از حصول بیشترین مقدار شاخص سرعت رشد محصول و كمترین میزان فتوسنتز، هدایت روزنه‌ای و تعرق از تراكم 100 بوته در مترمربع بود. به‌طور كلی در این تحقیق اگرچه رقم شهداد برتری معنی‌داری در سرعت رشد نسبی و سرعت رشد محصول نسبت به دو اكوتیپ بم و رودبار داشت ولی عملكرد خشك كل و خشك برگ این اكوتیپ‌ها با یكدیگر تفاوت معنی‌داری نداشت. نتایج این تحقیق نشان داد كه تراكم 100 بوته در مترمربع این گیاه برای سال اول كاشت از نظر عملكردی مناسب‌تر از سایر تراكم‌ها بوده ولی برای سال‌های دوم به بعد با توجه به رشد پیكره گیاه نیاز به تحقیق بیشتر می‌باشد.
چكيده لاتين :
Introduction
One of the most important factors to obtain the maximum performance or yield in every climatic condition and for each plant varieties is determining the optimum plant density. Henna (Lowsonia inermis L.) is a perennial plant with high value in terms of having medicinal properties and industrial applications. The dye which is derived from green leaves of henna is used for decorating the body with intricate designs and the principle coloring matter is lawsone, 2-hydroxy-1, 4-naphthoqunone. The main purpose of this study was to evaluate the agro-physiological reaction of different henna ecotypes to different planting densities in Kerman weather conditions.
Materials and Methods
The study was carried out as a factorial experiment based on complete randomized block design with three replications in Shahid Bahonar University in 2015. The experiment consisted of four plant densities (25, 33, 50 and 100 plants m-2) and three ecotypes (Shahdad, Roodbar and Bam). Due to its small seeds and germination problems the planting method used was transplanting. In this study, growth indices such as leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), leaf area ratio (LAR), specific leaf area (SLA), specific leaf weight (SLW), leaf area duration (LAD) and biomass duration (BMD) were calculated. The net photosynthesis, stomatal conductance and transpiration rate were measured in the middle of growing period by photosynthesis meter (CI-340 model, CID Bio- Science companies, USA). At the end, the results were analyzed using the SAS v. 9.1 and MSTATC software’s and diagrams were drawn by Excel software.
Results and Discussion
The results showed that the studied ecotypes were significantly different in terms of CGR, RGR and stomatal conductance. The highest average of CGR belonged to Shahdad ecotype while there was no significant difference between Roodbar and Bam ecotypes in this case. Shahdad ecotype with the RGR of 0.018 g.g.day had the highest average of this trait. This difference could be due to physiological, morphological and chemical factors as well as allocating pattern of photosyntates, all affects the relative growth rate. The maximum value of stomatal conductance was recorded for Shahdad ecotype (234.6 mmol m-2 s-1), that was not significantly different with Bam ecotypes (229.6 mmol m-2 s-1). There are some reports showing that the number of stomata per unit of leaf area may be changed with plant species and varieties. The differences in studied densities were statistically significant for the measured traits. Results showed that the maximum of CGR was recorded for 100 plants m-2 density. Increase in CGR at the higher densities could be due to the increased number of plants per unit area producing a higher leaf area index. In this research LAI increased with increasing in planting density and the highest average of this trait was obtained from 100 plants m-2. LAD and BMD were affected significantly by planting density. The results of mean comparisons showed that average of LAD and BMD decreased with increasing in plant density from 50 to 100 plants m-2. The same result was obtained for net photosynthesis, transpiration rate and stomatal conductance. Low net photosynthesis in 100 plants m-2 density could be due to high competition between plants for light and food absorption, increase in shading and consequently increasing in respiration. The results showed that total dry yield and leaf dry yield were significantly affected by planting densities. The highest and lowest values of mentioned traits belonged to densities of 100 and 25 plants m-2 respectively.
Conclusions
Generally between ecotypes evaluated in terms of performance, there was no difference in Kerman weather conditions. Also the highest yield was belonged to100 plants m-2 density. It should be noted that henna is a perennial plant and this planting density for the first year is economically justified but for more than one year old plants, according to changes in body size of the plant, research on the appropriate density seems to be necessary.
