Resistance Evaluation for Native Potato Accessions against Late Blight Disease and Potato Cyst Nematodes by Molecular Markers and Phenotypic Screening in India

Abstract

The potato originated in southern Peru and north-western Bolivia (South America). However, native accessions have also been cultivated in India for many years. Late blight, caused by the fungus Phytophthora infestans, is the most devastating potato disease, while potato cyst nematode (Globodera spp.) (PCN) is another economically significant quarantine-requiring pest in India. In this study, we have generated a new Indian native collection of 94 potato accessions collected from different parts India. These accessions were screened against late blight and potato cyst nematode resistance by using gene-based molecular markers and phenotypic screening methods. Marker assisted selection using R1 gene-specific marker CosA₂₁₀ revealed a late blight resistance gene in 11 accessions. PCN resistance bands were found in 3 accessions with marker TG689₁₄₁, 5 accessions with marker 57R₄₅₂, and 1 accession having Gro1-4-1₆₀₂ marker for G. rostochiensis (Ro1,4), while 64 accessions amplified marker HC₂₇₆ indicating G. pallida (Pa2,3) resistance gene (GpaV_vrn QTL). On the other hand, phenotypic screening against late blight resistance under natural epiphytic conditions (hot-spot) revealed three accessions with high resistance, while others were resistant (1 accession), moderately resistant (5 accessions), susceptible (29 accessions), and highly susceptible (56 accessions). For G. rostochiensis (golden cyst nematode) and G. pallida (white cyst nematode) resistance, accessions were grouped into highly resistant (3, 3), resistant (0, 2), moderately resistant (6, 29), susceptible (32, 30), and highly susceptible (53, 30), respectively, for the two PCN species. Collectively, we identified promising accessions with high resistance to late blight (JG-1, Kanpuria Safed, and Rangpuria), and also highly resistant to both Globodera species (Garlentic, Jeevan Jyoti, and JG-1). Our findings suggested that these accessions would be useful for late blight and PCN resistance breeding, as well as future molecular studies in potatoes.

Keywords: late blight; molecular marker; phenotype screening; potato cyst nematode; resistance.

Figure 1

Tuber phenotypes of promising Indian native potato accessions identified based on molecular and phenotypic screening against late blight and potato cyst nematode resistance.

Figure 2

Evaluation of Indian native potato collections for late blight (Phytophthora infestans) resistance R1 gene by using CosA₂₁₀ marker. Yellow asterisk indicates the presence of late blight resistance band (210 bp) in the accessions, viz., NJ-78 (#1), NJ-12 (#10), NJ-47 (#21), VK/JG-2 (#26), Phulwa White (#40), NJ-62 (#57), Var 3797 (#61), Australian White (#68), Aruconia (#74), Assamia Aloo (#76), and Lal Gulab (#87). M = 100 bp DNA ladder.

Figure 3

Evaluation of Indian native potato accessions possessing potato cyst nematode (G. rostochiensis Ro1, 4) resistance H1 gene by using molecular markers. (a) TG689₁₄₁ marker showed presence of resistance band (141 bp) in three accessions, viz., Rangpuria, Jeevan Jyoti, and JG-1. (b) 57R₄₅₂ marker showed presence of resistance band (452 bp) in five accessions, viz., Rangpuria, Garlentic, NJ-47, Jeevan Jyoti, and JG-1. M = 100 bp DNA ladder.

Figure 4

Phenotypic screening of Indian native potato collections under natural epiphytotic field conditions (hot-spot) for late blight resistance (a) at Kufri hills, Himachal Pradesh, India, and in the pots for potato cyst nematode resistance through root ball technique (b) at Kufri showing highly resistant accessions (e.g., Jeevan Jyoti and Garlentic) to both PCN species.