پديد آورندگان :
مندني، فرزاد دانشگاه رازي - گروه مهندسي توليد و ژنتيك گياهي، كرمانشاه , خاني، كيانوش دانشگاه رازي - گروه مهندسي توليد و ژنتيك گياهي، كرمانشاه , جلالي هنرمند، سعيد دانشگاه رازي - گروه مهندسي توليد و ژنتيك گياهي، كرمانشاه , سعيدي، محسن دانشگاه رازي - گروه مهندسي توليد و ژنتيك گياهي، كرمانشاه
كليدواژه :
تنش كمبود رطوبت , جذب تشعشع , شاخص هاي رشد , عملكرد دانه , كارايي مصرف تشعشع
چكيده فارسي :
اين تحقيق با هدف بررسي نقـش باكتريهـاي تقويت‌كننده رشد بر برخي از مهم‌ترين ويژگيهاي بوم شناختي فيزيولوژيك سويا (.Glycine max L) تحت رژيم هاي مختلف رطوبتي به‌صورت كرت هاي خرد شده فاكتوريل در قالب طرح بلوكهاي كامل تصادفي در مزرعه تحقيقاتي پرديس كشاورزي و منابع طبيعي دانشگاه رازي با سه تكرار در سال 1396 اجرا شد. تيمارهاي آزمايش شامل رژيمهاي مختلف رطوبتي (I1: قطع آبياري از مرحله پرشدن دانه ها تا انتهاي دوره رشد، I2: قطع آبياري از مرحله پايان تشكيل غلاف تا انتهاي دوره رشد و I3: آبياري كامل در تمام طول فصل رشد) بدون تنش آبياري در حدود 50 درصد تخليه رطوبت) به‌عنوان عامل اصلي و سويه هاي باكتري تقويت‌كننده (B1: بدون باكتري، B2: Bacillus subtilis، B3: Bacillus licheniformis) و ارقام سوياي كوثر، M9 و TMS به‌عنوان ديگر فاكتورها در نظر گرفته شد. صفات مورد ارزيابي شامل شاخص سطح برگ، روند جذب تشعشع، سرعت رشد محصول، سرعت رشد نسبي، وزن خشك كل، كارايي مصرف تشعشع و عملكرد دانه بود. نتايج نشان داد كه با افزايش تنش خشكي ويژگيهاي مورد ارزيابي ارقام مختلف سويا به‌شدت كاهش يافت. كاربرد سويه هاي مختلف باكتري به‌شدت منجر به بهبود ويژگيهاي مورد ارزيابي شد. بالاترين شاخص سطح برگ (6/7)، روند جذب تشعشع (18/2 مگاژول در مترمربع)، سرعت رشد محصول (20/6 گرم در در مترمربع در روز)، وزن خشك كل (1104/7 گرم در مترمربع) و كارايي مصرف تشعشع (1/165 گرم در مگاژول) مربوط به رقم TMS و در شرايط آبياري كامل + تلقيح باكتري ليكني فورميس وكم‌ترين ميزان صفات مذكور مربوط به رقم كوثر و در شرايط قطع آبياري از اواسط تشكيل غلاف + بدون تلقيح باكتري بود. عملكرد دانه سويا به‌طور معني داري تحت تأثير تيمارهاي آزمايش قرار گرفت، به‌طوريكه بيش‌ترين عملكرد دانه به‌ميزان 380/9 گرم در مترمربع مربوط به رقم TMS در تيمار آبياري كامل + تلقيح باكتري سوبتيليس بود و كم‌ترين آن به‌ميزان 134/2 گرم در مترمربع مربوط به رقم كوثر بود كه در تيمار قطع آبياري از اواسط تشكيل غلاف + بدون باكتري مشاهده شد. به نظر ميرسد در صورت كاهش مقدار آب قابل دسترس، تلقيح با باكتريهاي تقويت‌كننده رشد گياه منجر به افزايش تحمل به تنش كمبود آب به‌ويژه در شرايط تنش ملايم مي گردد.
چكيده لاتين :
Introduction
Water scarcity and frequent droughts are becoming a serious problem particularly in the context of alarming predictions
of climate change in the world. Within the arid and semi-arid regions, water availability is a major limitation for crop
production. Thus, it is necessary to improve yield and the efficient utilization of limited available water in the irrigated
agroecosystems. One possibility to enhance crop yield under water limitation is using soil microorganisms that increase
the radiation and water efficiency and uptake capacity. Among these potential soil microorganisms, plant growthpromoting rhizobacteria (PGPR) are the most promising, including all bacteria inhabiting the rhizosphere and the
rhizoplane able to simulate plant growth and yield. Therefore, the objective of the present study was to evaluate the
effects of the PGPR on the ecophysiological characteristics of soybean under different moisture regimes.
Material and Methods
The field experiment was conducted during 2016 at the research farm of Campus of Agriculture and Natural Research,
Razi University, Kermanshah, Iran (34°, 19´ N, 47°, 50´ E with 1320 m altitude). A split plot factorial experiment was
conducted based on randomized complete block design. Main plots had three irrigation regimes in which irrigation was
cut based on the soybean stages (I1: water deficit stress from mid pod development stage to maturity stage; I2: water
deficit stress from grain filling development stage to maturity stage; and I3: optimum irrigation in all development
stages) and sub-plots were composed of plant growth-promoting rhizobacteria (PGPR) (B1: no bacteria; B2: Bacillus
subtilis; and B: Bacillus licheniformis) and soybean cultivar (TMS, M9 and Kosar). The experimental plots were
irrigated based on furrow method. I3 treatment were irrigated every 7 days until the end of the growing period while in
the I1 and I2 treatments, the plots were irrigated every 7 days until the start of the water deficit stress. In order to
inoculate with the PGPR, the soybean seeds were plunged in a 1:10 (v:v) solution of liquid culture and distilled water,
respectively for 10 minutes. All seeds including inoculated and no inoculated seeds oven-dried at 30 ℃ for 5 h. Finally,
the soybean inoculated seeds by PGPR were inoculated by Rhizobium japonicum before sowing and cultivated
immediately at 4 to 5 cm soil depth. The evaluated traits were the leaf area index (LAI), radiation absorption (RA), crop
growth rate (CGR), relative growth ratio (RGR), total dry weight (TDW), radiation use efficiency (RUE) and Grain
yield (GY).
Results and Discussion
The results indicated that the water deficit stress reduced the LAI, RA, CGR, RGR, TDW, RUE and GY of soybean.
The PGPR application improved all measured traits of soybean in all irrigation regime treatments. The highest LAI
(6.7), RA (18.2 MJ.m-2), CGR (20.6 g.m-2.d-1), TDW (1104.7 g.m-2) and RUE (1.165 g.MJ-1) were related to TMS
cultivar in the optimum irrigation and B. licheniformis treatment and the lowest them were related to Kosar cultivar
under water deficit stress from mid pod development stage to maturity stage and no bacteria treatment. The greatest GY
(380.9 g.m-2) was related to TMS cultivar which was observed in the optimum irrigation and B. licheniformis treatment
and the lowest GY (134.2 g.m-2) was related to Kosar cultivar which was observed in the water deficit stress from mid
pod development stage to maturity stage and no bacteria treatment. In this study, B. licheniformis compared to B.
subtilis presented a more effective improvement in soybean LAI, RA, CGR, RGR, TDW, RUE and GY.
Conclusion
It seems that the PGPR could promote the soybean growth and yield via increasing the root system and more uptake of
water in the rhizosphere. Nevertheless, as the results showed, the more effects of the PGPR were observed in the I2
treatment compared to other treatments. The PGPR actually could promote the soybean growth and yield in the mid
water deficit stress.
