بررسي برخي صفات فيزيولوژيك، عملكرد دانه و اجزاي آن در ارقام ذرت تحت شرايط تنش خشكي و كاربرد مايكوريزا

Study of some physiological traits, grain yield and its components in maize cultivars under drought stress conditions and mycorrhiza application

بمنظور بررسي واكنش‌ ارقام‌ ذرت به كم‌آبي در شرايط كاربرد و عدم كاربرد قارچ مايكوريزا (Glomus mossea) بر روي برخي صفات ذرت آزمايشي به صورت اسپليت فاكتوريل بر پايه‌ ‌طرح بلوك‌هاي‌ كامل تصادفي طي دو سال 1394 و 1395 در ايستگاه تحقيقاتي دانشكده ‌كشاورزي دانشگاه‌ آزاد اسلامي واحد تبريز انجام شد. عامل اصلي شامل كم‌آبي بر اساس تبخير از تشتك كلاس A در دو سطح ‌70 ميلي‌متر (به عنوان شاهد) و 140 ميلي‌متر (به عنوان تنش) و عامل فرعي شامل 14 تركيب فاكتوريل كاربرد و عدم كاربرد قارچ مايكوريزا (گونه گلوموس موسه) روي هفت رقم ‌ذرت (260، ‌301،400، 4015، 703،‌704و 705) بودند. صفات مورد اندازه‌گيري مشتمل بر محتوي رطوبت نسبي برگ، ميزان شاخص كلروفيل، شاخص سطح برگ، تعداد بلال در بوته، طول بلال، تعداد دانه در رديف، تعداد رديف دانه، وزن 300 صد دانه و عملكرد‌ دانه بود. نتايج حاصل از تجزيه مركب داده‌ها نشان داد كه اثر متقابل سال در تنش در رقم و همچنين تنش در رقم در مايكوريزا روي عملكرد دانه معني‌دار بود. بر اساس مقايسه ميانگين داده‌ها بيشترين عملكرد دانه مربوط به سينگل‌كراس 301 و در شرايط بدون تنش با ميانگين 760 گرم بر متر مربع بود. در حالي كه كمترين عملكرد دانه مربوط به سينگل‌كراس 4015 در شرايط كم‌آبي با ميانگين 392 گرم بر متر مربع بود. بيشترين عملكرد در شرايط بدون تنش و تنش كم‌آبي به ترتيب در سينگل‌كراس 703 و 301 و در شرايط كاربرد مايكوريزا به ترتيب با ميانگين 765 و 720 گرم بر متر مربع بود. به عبارتي قارچ مايكوريزا در برخي از ارقام در شرايط تنش اثر مثبت روي عملكرد داشت. برآورد همبستگي بين صفات نشان داد كه در هر دو شرايط آبياري نرمال و تنش كم‌آبي، عملكرد دانه بيشترين همبستگي را با وزن 300 صد دانه داشت.

Maize (Zea mays L.) is one of the most important crops and after wheat and rice, it has the third place among cereals. Water in arid and semi arid regions is one of the most important limiting factors for crop production. an‎d water resources in the country are limited, new hybrids that are suitable for drought tolerance and their economic performance should be developed. Various studies have shown that mycorrhizal fungi can have adverse effects on drought stress in plants The reduction of arbacterial mycorrhiza with the roots of most plants has a similar relationship with the plant in the absorption of mineral elements, soil and In addition to enhancing food absorption, this fungi may stimulate growth regulators, increase photosynthesis, improve osmotic pressure regulation in drought conditions, and increase resistance to environmental stress. Materials and methods To investigate the reaction of some physiological traits, grain yield and its components of maize cultivars to water deficit under the conditions of mycorrhizal application and non-application, A split factorial experiment based on randomized complete block design was performed during two years 2015 and 2016 , at the Research Station of the Faculty of Agriculture, Islamic Azad University, Tabriz Branch. The main factor was drought stress based on evaporation from class A pan with two levels of 70 mm (as control) and 140 mm (as stress) and subsidiary factor including 14 factorial combinations of application and non-application of mycorrhiza on seven maize cultivars (260, 301, 400, 4015, 703, 704 and 705). The traits measured included relative water content, chlorophyll index, leaf area index, number of ear per plant, ear length, number of seeds per row, row number of seeds, weight 300 hundred seeds and grain yield. Results The results of combined analysis of the data showed that the interaction of year in stress in cultivar and also stress in the cultivar in Mycorrhiza was significant on grain yield. Based on the comparison of mean values, the highest seed yield was related to single-cross 301 and in non-stress conditions. While the lowest grain yield was related to single-cross 4015 in drought stress conditions. The highest yield in non-stressed conditions and drought stresses was in single-cross 400 and 301 respectively under microscopic conditions. In other words, mycorrhiza had a positive effect on some of the cultivars under stress conditions. The correlation coefficients between traits showed that in both conditions of normal irrigation and drought stress, grain yield had the highest correlation with 300 grain weight. Conclusion The results of this study showed that the occurrence of drought stress in corn field from the 6th leaf stage to seed had a negative and significant effect on grain yield. The response of the cultivars was different under stress and non stress conditions. Regarding the existence of significant differences in grain yield between two levels of application and non-application of mycorrhiza under water resources constraints, it is possible to use precise irrigation management and mycorrhiza application in some The cultivars significantly reduced dehydration losses on corn grain yield. The correlation between seed yield with 300 grain weight, number of seeds per row and number of grain rows were positive and significant