Field Resistance in Bread Wheat to Russian Wheat Aphid, Diuraphis noxia Under Flood Irrigation

Abstract

አህፅሮት

የሩሲያ ክሽክሽ (Diuraphis noxia) በዓለም ላይ በሰፊው የተሰራጨ ተባይ ሲሆን የስንዴ ምርትን እስከ 93 በመቶ ሊያወድም ይችላል፡፡ እንዲሁም ይህ ክሽክሽ ቅዉም ሰባሪዎች ስላለው ክሽክሹን የሚቋቋሙ ዝርያዎች የሚያገለግሉት ለተወሰነ አካባቢ ብቻ ነው፡፡ ይህም በመሆኑ ከኢትዮጵያ ውጭ ባሉ ስንዴ አብቃይ አገሮች ክሽክሹን የሚቋቋሙ 49 ብዝሀ-ዘሮችን በማስገባት ደብረ ዘይት ላይ ለሁለት ዓመት (2007 እና 2008 ዓም) መስኖ እና የተፈጥሮ ወረራ በመጠቀም ተፈትሿል፡፡ ሙከራው የተካሄደው 7 በ 7 በሆነ የላቲስ ንድፍ ላይ ብዝሀ-ዘሮችን በመዝራት ነው፡፡ ሙከራ ከተደረገባቸው 49 ብዝሀ-ዘሮች መካከል ከሩሲያ ክሽክሽ ወረራ ነፃ የሆነ ብዝሀዘር ባይኖርም በክሽክሽ አህዛብ ብዛት ግን ሰፊ ተለያይነት ነበር፡፡ በሁለቱም ዓመት ከፍተኛ ቁጥር ባለው ክሽክሽ የተወረሩና ከፍተኛ ጥቃት የደረሰባቸው  ብዝሀ-ዘሮች ትንሽ ቁጥር ባለው ክሽክሽ የተወረሩ እና ከፍተኛ ቅውሞሽ ያሳዩ ብዝሀ-ዘሮች ነበሩ፡፡ ቀሪዎች ብዝሀ-ዘሮች ግን መካከለኛ የቅውሞሽ ደረጃ ነበራቸው፡፡ ስለሆነም የሩሲያ ክሽክሽ አህዛብ ዕድገት በተለያዩ ብዝሀ-ዘሮች የተለያየ ነበር፡፡ በተጨማሪም በተወረሩ ቀዘባዎች (መቶኛ) እና በአንድ ቀዘባ ላይ የነበረው የክሽክሽ ብዛት መካከል ቀጥተኛ ግንኙነት አልነበረም፡፡

Abstract

The Russian wheat aphid (RWA) (Diuraphis noxia) is cosmopolitan pest and yield losses of up to 93% have been reported in different wheat growing countries. It also has a high degree of biotypic diversity that necessitates the development and utilization of location specific resistant wheat varieties. Thus, 49 wheat genotypes known to be resistant to RWA in other countries were evaluated using natural infestation in 7x7 Simple Lattice for two seasons under flood irrigation at Debre Zeit, Ethiopia. In both seasons none of the tested genotypes were free of RWA infestations. However, in the 2015 season, there was statistically significant difference among genotypes in RWA intensity in all sampling dates, whereas in the 2016 season there was the statistically significant difference among genotypes in RWA intensity in the first three sampling dates but not in the later three sampling dates. The genotypes CIMMYT 109, CMYRWA-7, CMY RWA 36, CMY RWA 103, Correll, SH01-Correll, IG41560, IG 41556, IG 107166, KRWA-9, KRWA 152, SHK01-A26-15, SHK01-B32-59, SHK01-C96-149 and SHK01-D12-167 were highly susceptible to RWA, while CMY RWA 101, PI 625140-1, R-765-RWA-152, SHK01-A36-22, SHK01-B10-46, SHK01-B30-58, SHK01-B35-60, SHK01-B84-89 and SHK01-D37-184 were highly resistant. The remaining genotypes were moderately resistant/ susceptible. As a result the pattern of population increase on the different genotypes was variable across sampling dates. There was no apparent relationship between percent infested tillers and number of aphids per tiller.