نوع مقاله : مقالات پژوهشی
نویسندگان
1 استاد گروه علوم باغبانی، دانشکده کشاورزی، دانشگاه فردوسی مشهد
2 دکتری علوم باغبانی (گرایش میوهکاری)، گروه علوم باغبانی، دانشکده کشاورزی، دانشگاه فردوسی مشهد
3 دکتری کشاورزی (گرایش اگرواکولوژی)، گروه زراعت و اصلاح نباتات، دانشکده کشاورزی، دانشگاه فردوسی مشهد
چکیده
کاهش عملکرد پسته ارتباط نزدیکی با اختلالات میوه و تنشهای مختلف محیطی دارد. پلیآمینها گروهی از تنظیمکنندههای رشد گیاهی هستند که تاثیر مثبتی بر رشد و توسعه گل و میوه در برابر تنشها دارند. بنابراین، هدف این مطالعه ارزیابی تاثیر پلیآمینها در شرایط کمآبی محل آزمایش بر صفات رویشی، ویژگیهای میوه و عملکرد درختان پرمحصول و کم محصول پسته رقم ̕اکبری̔ بود. برای این منظور، آزمایشی به صورت کرتهای خرد شده در زمان بر پایه طرح بلوکهای کامل تصادفی با سه تکرار و هفت تیمار شامل محلولپاشی پلیآمینهای پوترسین، اسپرمیدین و اسپرمین در غلظتهای صفر (شاهد)، 1/0 و 1 میلیمولار در دو مرحله زمانی تمام گل و دو هفته بعد از تمام گل در منطقه فیضآباد مهولات استان خراسان رضوی در سال 1395 انجام شد. نتایج نشان داد که محلولپاشی پلیآمینها در درختان کم محصول با وجود کاهش درصد پوکی تأثیر معنیداری بر عملکرد پسته نداشت. با اینوجود در درختان پرمحصول، کاربرد این تنظیمکنندهها بهویژه پوترسین سبب کاهش ریزش میوه و افزایش شاخص سبزینگی، تعداد دانه در خوشه و عملکرد در مقایسه با شاهد شد. با توجه به نتایج همبستگی، تاثیر مثبت پلیآمینها بر بهبود عملکرد در درختان پرمحصول عمدتاً به دلیل جلوگیری از ریزش میوه و افزایش تعداد دانه در خوشه بود. بهطوریکه میزان تولید در شاخه در تیمارهای پوترسین، اسپرمین و اسپرمیدین در غلظت 1/0 میلیمولار به ترتیب 2/46، 6/14 و 2/15 درصد و در غلظت 1 میلیمولار به ترتیب 7/38، 7/24 و 9/19 درصد در مقایسه با شاهد افزایش داشت. همچنین محلولپاشی پلیآمین پوترسین دو هفته بعد از تمام گل نتایج بهتری در افزایش طول شاخه در درختان پرمحصول نشان داد. به طور کلی، نتایج این آزمایش نشان میدهد که محلولپاشی پوترسین در مقایسه با اسپرمین و اسپرمیدین در شرایط کمآبی میتواند بر بهبود صفات رویشی و زایشی و در نتیجه عملکرد درختان پسته رقم ̕اکبری̔ مؤثرتر باشد.
کلیدواژهها
عنوان مقاله [English]
Evaluation of the Effect of Exogenous Application of Polyamines on Growth, Nut Traits and Yield of ‘Akbari’ Pistachio Trees (Pistacia vera L.)
نویسندگان [English]
- Gholamhossein Davarynejad 1
- Mina Nurzadehnamaghi 2
- Ali Momen 3
1 Professor Department of Horticultural Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran
2 Ph.D. Gratuated (Pomology Tendency), Department of Horticultural Science, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran
3 Ph.D. Agriculture (Agroecology tendency), Agronomy Department, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran
چکیده [English]
Introduction: Pistachio (Pistacia vera L.) is an important horticultural crop that has high economic value. Pistachio trees display some physiological disorders including abscission of inflorescence buds, fruit abscission, blankness, non-splitting, early splitting and deformation of nuts. Unfavorable environmental conditions in most pistachio orchards and inadequate nutrition during the flowering time and after flowering has increased these problems in recent years. Polyamines such as putrescine, spermine and spermidine are some low molecular weight polycationic compounds that have been shown to play an important role as growth regulators in different stages of growth and development of buds, flowers and fruits and resistant plants to abiotic and biotic stress. Therefore, the objective of this study was to investigate the influence of polyamines in water scarcity condition on growth, nut traits and yield of ‘Akbari’ pistachio trees.
Materials and Methods: The study was carried out in growing season 2016 in a pistachio orchard (Pistacia vera L. cv Akbari) located in Feyzabad, Mahvelat, Khorasan Province, Iran (34° 40´ N latitude, 58° 25´ E longitude, and around 1253 m above sea level). The climate of the experimental area was arid and semi-arid. The mean annual precipitation was about 171 mm. The irrigation of orchard trees was at 36-day intervals. The experiment was conducted as split plot based on a randomized complete block design with three replications and seven treatments including polyamines spray of Putrescine (Put), Spermine (Spm) and Spermidine (Spd) at concentrations of zero (control), 0.1 and 1 mM on “on” and “off” pistachio trees cultivar Akbari at two-time stages full bloom (FB) and two weeks after full bloom (2WAFB). Leaf chlorophyll index was recorded using the chlorophyll meter (SPAD-502, Konica Minolta, Japan). Leaf area from fully expanded leaves was measured by Digital Leaf Area Meter (LI-3100c). The length and diameter of current-year shoots were measured at harvest time. The percentage of flower bud abscission and fruit abscission were calculated on marked shoots. The yield was calculated by weighting the total dried split nuts separated from each shoot. The data were subjected to analysis of variances (ANOVA) using the SAS software (SAS version 9.1). Difference between means was compared using the least significant difference test (LSD) at 5% level (p ≤ 0.05).
Results and Discussion: Results showed that among the treatments, Put (0.1 and 1 mM) and Spm (0.1 mM) applied in the “on” trees significantly increased leaf chlorophyll index. Also, Put spray at two weeks after full bloom indicated better results in increase of length shoot in ‘on’ trees. All of the polyamines reduced fruit abscission in the “on” trees however, Put at 0.1 and 1 mM concentrations with 11.3 and 11.1% was more effective in decreasing the percentage of fruit abscission compared to other treatments. Fruit abscission of pistachio is assumed to be related to improper fertilization, the dominance of fruits in a cluster or abnormalities of reproductive organs. Polyamines have been suggested to improve fertilization, and subsequent embryo and fruit development. It also has been reported that common precursor of S-adenosylmethionine (SAM) needed for synthesizing both of PAs and ethylene. Thus, it seems that polyamines reduce the abscission of fruits by the improvement of embryo growth and development or by antagonism with ethylene, possibly by competing for S-adenosylmethionine (SAM). Our study indicated that all of the polyamines decreased the percentage of blank nuts in the “off” trees especially two weeks after full bloom. The results showed that Put (0.1 and 1 mM) and Spd (0.1 mM) were very effective in increasing number of nuts per cluster. Number of nuts per 100 g, split nuts, and kernel percentage did not differ significantly among treatments. Yield variations were not significantly affected by polyamines in in the “off” trees, but in ‘on’ trees, polyamines of Put, Spm and Spd at 0.1 mM concentration by 46.2, 14.6 and 15.2% and at 1 mM concentration by 38.7, 24.7 and 19.9% increased yield compared to control, respectively. Given to correlation results, the positive effect of polyamines on yield improvement in ‘on’ trees was mainly due to the prevention from fruit abscission and enhancement no. of nuts per cluster.
Conclusion: Results showed that application of polyamines treatments in ‘off’ trees only on blank nuts and in ‘on’ trees on leaf chlorophyll index, fruit abscission, No. of nuts per cluster and yield was effected. Foliar application of polyamines was more effective in improving traits of shoot length, leaf area and blank nuts two weeks after full bloom compared to full bloom. The results of this study showed that these plant growth regulators, especially putrescine, had the potential to improve growth, yield and reduce physiological problems of pistachio under unfavorable environmental conditions.
کلیدواژهها [English]
- Inflorescence bud abscission
- Fruit abscission
- Putrescine
- Spermidine
- Spermine
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