A.I. Polinova, D.R. Zagirova, L.Yu. Kokaeva, I.I. Busko, I.V. Levantsevich, S.N. Elansky
A cikin 'yan shekarun nan, yanayin kula da dankalin turawa da hannun jari ya lalace a hankali a cikin Belarus. Matsayin wasu nau'ikan kwayoyin cuta masu cutarwa da yadda suke a cikin agrophytocenoses ya canza. Cututtukan mutane da yawa ba kawai cututtukan da ke yaɗuwa ba ne (ƙarshen ɓarna, alternaria, kowane nau'in scab, bacteriosis, bushewar fusarium) ya ƙaru, amma kuma sabo ne, waɗanda ba su da cikakken nazari, kamar su lalacewar ruwa mai rauni (Fig. 1). Wannan cutar, wacce ke faruwa a Indiya, Asiya ta Tsakiya da sauran ƙasashen kudanci, an lura da ita a yankunan Gomel, Brest, Grodno da Minsk na Belarus. Kamar sauran oomycetes da ke zaune a cikin ƙasa, P. yana haifar da mummunar lalacewa a yanayin danshi mai yawa - a yankunan da ba su da kyau, a lokacin tsawan ruwan sama (Taylor et al., 2008).
A cikin Belarus, an lura da yaduwar cutar a cikin shekaru tare da ƙaruwar zafin jiki na lokacin girma: a cikin wasu rukuni na dankali, 8-10% na tubers ya shafa. Raunin ruwa na tubers na iya haifar da mummunar lalacewa, wanda rashin lalacewar iri ne ke haifar da shi, matakan kariya da saurin ci gaban cutar idan lalacewar tubers (Zhuromskaya, 2003; Ivanyuk et al., 2005). Cutar ta shafi tubers kawai. A cikin Rasha, raunin ruwa mai rauni ba shi da mahimmanci.
A cikin wannan aikin, mun binciki nau'ikan 4 na abubuwan da ke haifar da lalacewar ruwa mai rauni wanda aka ware daga tubers dankalin turawa na nau'ikan Vektar Belorussian, Skarb da kuma zababbun matattara a cikin taskokin Cibiyar Kimiyya da Kwarewa ta Kwalejin Kimiyya ta Kasa ta Belarus don Dankali da ciyayi (yankin Minsk). Makasudin binciken shine don tantance jinsin kebantattun kebantattun wurare, tsananin cutar su dangane da tubers dankalin turawa, don tantance ci gaban a yanayin yanayin yanayi daban daban da kuma juriya ga metalaxyl.
Mycelium na abubuwan da aka kebanta sun girma ne akan matsakaicin matsar ruwan wake (180 g na daskararriyar Peas an tafasa ta tsawan mintuna 10 a cikin lita 1 ta ruwa mai narkewa, bayan an gama dasu an tsaresu tsawon mintuna 30 a yanayi daya); An ware DNA daga kowace damuwa. Don keɓancewar DNA, mycelium daskararre aka sanya shi cikin nitrogen mai ruwa, aka sanyashi a cikin maɓallin CTAB, sa'annan aka hana shi maganin chloroform. An adana DNA a cikin ruɓaɓɓen ruwa a –1 ° С. Tattaunawa akan jerin nucleotide na wasu yankuna na musamman (yankuna na kwayoyin ribosomal na nukiliya 20S da 18S, da kuma kwayar cutar ta ITS5,8) wacce aka kara amfani da ita ta amfani da farkon ITS1 da ITS1 (Fari, 2), ya nuna cewa nau'ikan da aka yi karatun suna cikin nau'in Trow mafi girma na Pythium. (synonym Globisporangium Ultimate (Trow) Uzuhashi, Tojo & Kakish).
Dukkanin nau'ikan nazarin sun shafi yankewar Gala dankalin turawa da aka sanya a ɗakunan zafi. An samar da duhu mai duhu akan su, daga baya ya rikide zuwa ulce mai ratsa jiki sosai (Fig. 2). An gudanar da kamuwa da cutar ta hanyar sanya P. myimal mycelium a tsakiyar ɓangaren tuber.
An saka fayafan tuber ɗin da aka saka a + 22 ° C. Matsakaicin girma na yankin da abin ya shafa an lura da shi a cikin kwanaki 2 na farko, sannan yankin maƙarƙashiyar ya kasance kusan canzawa.
Wannan tsarin yana aiki ga dukkan nau'ikan binciken.
An kiyasta saurin ci gaban ƙwayoyin a kan matsakaicin oat agar a yanayin zafi na 5, 15, 24, da 34 ° C (Fig. 3). An lura da ci gaba a kowane yanayin zafi; an lura da matsakaicin girman girma a 24 ° C (kofin 86 mm kwata-kwata ya cika girma cikin kwana 2). A 15 da 34 ° C, haɓakar haɓakar ta ragu ƙwarai (ƙoƙon ya girma a cikin kwanaki 4 da 3, bi da bi).
A yanayin zafi na 15, 24, da 34 ° C, yawan ci gaban dukkan nau'ikan binciken bai bambanta ba. A zazzabi na 5 ° C, zafin P1 ya girma da sauri fiye da wasu (20 mm a ranar 4), P4 - da ɗan kaɗan (10 mm a rana 4), P2 da P3 kusan ba su girma.
Ya kamata kuma a sani cewa a zafin jiki na 24 ° C girma ya fara nan da nan bayan dasa shuki a kan tasa, a yanayin zafi na 15 da 34 ° C akwai jinkiri a farkon farawar aiki ta kwana 1, kuma a 5 ° C - ta kwana 2.
Metalaxyl (da isomer mefenoxam) ana ɗaukarsu azaman magunguna mafi inganci don kula da oomycetes na ƙasa. Metalaxil zai iya shiga cikin tubers kuma ya samar (koda a cikin ƙananan ƙananan) kariya ta dogon lokaci (Taylor et al., 2008; Bruin et al., 1982). Koyaya, tasirin metalaxyl yana raguwa sosai bayan bayyanar nau'in juriya a cikin jama'a. An samo ƙananan ƙwayoyi masu ƙarfi a cikin yankuna da yawa na Amurka (Taylor et al., 2002). Babu bayanai game da juriya na Belarusian P. mafi ƙarancin damuwa zuwa metalaxyl, sabili da haka an yanke shawarar gwada juriyarsu da maganin a cikin wannan aikin.
Nazarin mai saukin kamuwa da kayan gwari metalaxyl an gudanar dashi akan oat agar matsakaici tare da ƙari na kayan gwari a wurare daban-daban (Pobedinskaya, Elansky, 2014).
Ilimin binciken yana da wasu bambance-bambance a cikin juriya ga metalaxyl (Table 1). Sabili da haka, a cikin haɗarin kayan gwari na 1 mg / l, haɓakar cutar P4 gabaɗaya ta tsaya, sauran ragowar kuma sun ragu sosai. Insananan P1 da P2 sun yi girma a hankali a kan matsakaici tare da ƙimar metalaxyl na 10 mg / L. Concentrationididdigar tasiri mai tasiri EC50 (ƙaddamar da kayan gwari yana rage saurin haɓakar ƙwayar ta sau 2 dangane da sarrafawa) don duk matsalolin bai kai 1 mg / L. Don haka, duk nau'ikan da aka bincika sun kasance masu saukin kamuwa da metalaxyl; an nuna yana da matukar tasiri wajen hana ci gaban P. ultimum.
A cewar Bruin et al. (1982) bayan maganin tsirrai a lokacin ciyayi tare da metalaxyl a kashi 0,5 kg / ha, tarin kayan gwari a cikin tubers ya kai 0,055 μg / g a cikin periderm, 0,022 μg / g a cikin layin cortical, da 0,034 μg / g a tsakiyar ɓangaren tuber. Dangane da bayananmu, wannan maida hankali na metalaxyl bai isa ba don magance cutar, amma zai iya jinkirta ci gabanta.
Lokacin girma a kan matsakaicin oat, dukkan nau'ikan iri sunada wadatar zafin nama (Fig. 4), wanda yake na P. Irirƙirar ɓarna iri-iri ya nuna babu alamun alamun rashin daidaituwa na ciyayi - kofuna an rufe su da mycelium.
Bayanan da aka samo sun nuna cewa P. mafi girma shine phytopathogen wanda ke iya saurin ci gaba cikin kewayon zafin jiki mai yawa, gami da a ma'aunin zafin jiki na 5 ° C. Yana da lahani ga kyallen takarda na tubers dankalin turawa da sifofin da zasu iya rayuwa na tsawon lokaci. Don haka, nau'ikan halittu ne masu hatsarin gaske wanda ke iya haifar da barazana ga aikin gona kuma yana buƙatar ƙarin bincike.
An gudanar da binciken ne tare da tallafin Gidauniyar Kimiyya ta Rasha (aikin N 14-50-00029).
Tebur 1. Sensitivity na P. ƙarancin damuwa zuwa metalaxyl
Iri | Matsalar Metalaxyl, mg / l | ||
0 (sarrafawa) | 1 | 10 | |
P1 | 63 | 6 | 0 |
P2 | 65 | 5 | 0 |
P3 | 59 | 0 | 0 |
P4 | 61 | 0 | 0 |
P1 | 105 | 10 | 3 |
P2 | 110 | 10 | 3 |
P3 | 95 | 0 | 0 |
P4 | 98 | 0 | 0 |
Kimanin. An bayar da adadin bayanai na awo 3.
An buga labarin a cikin mujallar "Kariyar Dankali" (A'a. 1, 2017)