Ābeļu (Malus x domestica (L.) Borkh) izturības pret kraupi (Venturia inaequalis (Cooke) Wint.) iedzimtība hibrīdajā selekcijas materiālā, veicot gēnu piramidēšanu
Date
2018
Authors
Lejniece, Kristīne Krista
Journal Title
Journal ISSN
Volume Title
Publisher
Latvijas Universitāte
Abstract
Ābeles ir komerciāli nozīmīgs kultūraugs visā pasaulē, bet ik gadu nozīmīgus bojājumus rada patogēnās sēnes Venturia inaequalis izraisītais ābeļu kraupis. Kraupja ierobežošana pārsvarā balstīta uz intensīvu un regulāru pesticīdu izmantošanu, tādējādi radot negatīvu ietekmi uz vidi un cilvēku veselību. Alternatīva ir izveidot kraupja rezistentas ābeļu šķirnes. Jau novērots, ka monogēna rezistence pret kraupi nav ilgnoturīga un to varētu uzlabot, iekļaujot vairākus rezistences gēnus vienā auga genotipā jeb gēnus piramidējot. Darba mērķis bija novērtēt un raksturot mājas ābeles (Malus × domestica ) izturības pret kraupi (ier. Venturia inaequalis.) iedzimtību un selekcijas procesa efektivitāti hibrīdu saimēs ar atšķirīgu vecākaugu ģenētisko rezistenci. Šim nolūkam analizēti 862 ābeļu hibrīdu paraugi, kuri sadalīti populācijās, atkarībā no vecākaugu genotipos sastopamiem rezistences gēniem (Rvi6 un Rvi5) un to kombinācijām (Rvi6 × ieņēmīga šķirne; Rvi6 × Rvi6 un Rvi5 × Rvi5). Lauka vērtēšana veikta 2016. un 2017. gadā, izmantojot starptautisku VINQUEST kraupja novērtēšanas metodiku, bet gēnus identificēja izmantojot specifiskos un SSR marķierus, vecākaugu genotipēšanā izmantoja 22 SSR molekulāros marķierus. Ir maz pētījumu, kuros kopīgi analizēti molekulārie un lauka kraupja izturības novērtēšanas dati, lai gan tie sniedz realistiskāku rezistences selekcijas procesa modeli. Pētījumā noteikts, ka ābeļu kraupja lauka izturību ietekmē ne tikai genotipā esošie rezistences gēni, bet ābeļu ģeogrāfiskā izcelsme, koka veselības stāvoklis un rezistence pret citām slimībām. Kraupja rezistences noturību nosaka ģenētiskie faktori, bet arī videi ir modificējoša ietekme. Izvērtējot selekcijā iekļauto rezistences gēnu iedzimtību, konstatēts, ka Rvi6 (Vf) un Rvi5 (Vm) kraupja rezistence pārmantojas saskaņā ar Mendeļa likumiem, un, veicot abu gēnu piramidēšanu pēcnācējos, tie pārmantojas kā atsevišķi gēni. Kopumā abu gēnu pārmantošana pēcnācējos nav ābeļu lauka izturības noteicošais faktors, jo lauka izturību pret kraupi ietekmē vairāku faktoru kopums.
Apple is a commercially important horticultural crop around the world, but every year important losses are made by apple scab caused by fungal pathogen Venturia inaequalis. Apple scab management is mostly based on intense and regular use of pesticides, resulting with negative environmental impacts and negative impacts of human health. An alternative is to create scab resistant apple trees cultivars. It has already been observed that monogenic resistance to apple scab is not durable and it could be improved by including multiple resistance genes in one plant genotype or making gene pyramiding. The aim of the study was to evaluate and characterize Malus domestica (Malus × domestica) resistance against apple scab (causal agent Venturia inaequalis) heredity and the effectiveness of the selection process in hybrid families with different parental resistance. For this purpose, samples of 862 apple hybrids has been analyzed. Samples are divided into populations, depending on the resistance genes (Rvi6 and Rvi5) occurred in the parent genotype and their combinations (Rvi6 × susceptible variety; Rvi6 × Rvi6 and Rvi5 × Rvi5). Field scoring has been performed in 2016 and 2017. Scorings are made using the international VINQUEST apple scab assessment methodology, but the genes were identified by using specific and SSR markers. In parent genotyping 22 SSR molecular markers has been used. There are only few studies that includes combined analyze of molecular and apple scab field resistance scoring data, although they can give more realistic pattern of resistance selection process. The study showed that the resistance of the apple scab in field is affected not only by resistance genes in genotype, but also the origin of apple cultivar, tree health status and resistance to other diseases. Apple scab resistance is determined by genetic factors, but the environment also has a modifying effect. The assessment of the heredity for resistance genes included in the breeding, it was found that the resistance genes Rvi6 (Vf) and Rvi5 (Vm) are inherited in accordance with Mendel's laws. The pyramiding of both genes in progeny discovered their separate inheritance. In general, the inheritance of both genes in progeny was not a main determining factor of apple field resistance tree, because the field's resistance to apple scab is influenced by a combination of several factors.
Apple is a commercially important horticultural crop around the world, but every year important losses are made by apple scab caused by fungal pathogen Venturia inaequalis. Apple scab management is mostly based on intense and regular use of pesticides, resulting with negative environmental impacts and negative impacts of human health. An alternative is to create scab resistant apple trees cultivars. It has already been observed that monogenic resistance to apple scab is not durable and it could be improved by including multiple resistance genes in one plant genotype or making gene pyramiding. The aim of the study was to evaluate and characterize Malus domestica (Malus × domestica) resistance against apple scab (causal agent Venturia inaequalis) heredity and the effectiveness of the selection process in hybrid families with different parental resistance. For this purpose, samples of 862 apple hybrids has been analyzed. Samples are divided into populations, depending on the resistance genes (Rvi6 and Rvi5) occurred in the parent genotype and their combinations (Rvi6 × susceptible variety; Rvi6 × Rvi6 and Rvi5 × Rvi5). Field scoring has been performed in 2016 and 2017. Scorings are made using the international VINQUEST apple scab assessment methodology, but the genes were identified by using specific and SSR markers. In parent genotyping 22 SSR molecular markers has been used. There are only few studies that includes combined analyze of molecular and apple scab field resistance scoring data, although they can give more realistic pattern of resistance selection process. The study showed that the resistance of the apple scab in field is affected not only by resistance genes in genotype, but also the origin of apple cultivar, tree health status and resistance to other diseases. Apple scab resistance is determined by genetic factors, but the environment also has a modifying effect. The assessment of the heredity for resistance genes included in the breeding, it was found that the resistance genes Rvi6 (Vf) and Rvi5 (Vm) are inherited in accordance with Mendel's laws. The pyramiding of both genes in progeny discovered their separate inheritance. In general, the inheritance of both genes in progeny was not a main determining factor of apple field resistance tree, because the field's resistance to apple scab is influenced by a combination of several factors.
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Keywords
Bioloģija , Malus × domestica , ābeļu kraupis , lauka izturība , SSR , molekulārie marķieri