Genetic parameters and correlations of collar rot resistance with important biochemical and yield traits in opium poppy (Papaver somniferum L.)

Abstract

Collar rot, caused by Rhizoctonia solani Kühn, is one of the most severe fungal diseases of opium poppy. In this study, heritability, genetic advance and correlation for 10 agronomic, 1 physiological, 3 biochemical and 1 chemical traits with disease severity index (DSI) for collar rot were assessed in 35 accessions of opium poppy. Most of the economically important characters, like seed and capsule straw yield per plant, oil and protein content of seeds, peroxidase activity in leaves, morphine content of capsule straw and DSI for collar rot showed high heritability as well as genetic advance. Highly significant negative correlation between DSI and seed yield clearly shows that as the disease progresses in plants, seed yield declines, chiefly due to premature death of infected plants as well as low seed and capsule setting in the survived population of susceptible plants. Similarly, a highly significant negative correlation between peroxidase activity and DSI indicated that marker-assisted selection of disease-resistant plants based on high peroxidase activity would be effective and survived susceptible plants could be removed from the population to stop further spread.

Downy mildew resistance in opium poppy: resistance sources, inheritance pattern, genetic variability and strategies for crop improvement

“…In such cases a simple selection model would be advantageous to obtain the desired gain because no additional gain can be achieved by using other sophisticated models (Singh et al 2003b). Similar to our results, Trivedi et al (2006) have also observed high heritability along with high values of genetic advance for seed and straw yield and DSI for collar rot. High heritability coupled with high GA and Genotypic coefficient of variation (GCV) for the traits like papaverine, thebaine and narcotine have also been reported in opium poppy (Yadav et al 2006).…”

“…The heritability estimates were high for most of the traits and ranged from 39% for diameter of the central capsule to 99.81% for seed yield/central capsule (Table 4). There have been similar reports of high heritability for characters like plant height, days to 50% flowering, days to maturity, leaf area per plant, straw and seed yield per plant, oil and protein content of seeds, morphine content of straw, DSI for collar rot (Trivedi et al 2006;Jain et al 2005;Pant et al 1999), morphine, codeine, thebaine and narcotine contents (Yadav et al 2006;Briza 1983). There have also been reports of low heritability of some characters like number of capsules per plant (Trivedi et al 2006;Briza 1983).…”

“…There have been similar reports of high heritability for characters like plant height, days to 50% flowering, days to maturity, leaf area per plant, straw and seed yield per plant, oil and protein content of seeds, morphine content of straw, DSI for collar rot (Trivedi et al 2006;Jain et al 2005;Pant et al 1999), morphine, codeine, thebaine and narcotine contents (Yadav et al 2006;Briza 1983). There have also been reports of low heritability of some characters like number of capsules per plant (Trivedi et al 2006;Briza 1983). However, heritability estimates may differ widely in the same crop and for same traits as it always refers to a defined population and specific experimental set up (Holland et al 2002).…”

“…Several independent studies in the past on the evaluation of the genetic variation in the cultivated germplasm lines of P. somniferum suggested limited to a large array of genetic variability for different characters (Trivedi et al 2006;Yadav et al 2006;Jain et al 2005;Singh and Shukla 2001;Bajpai et al 1999b). …”

Molecular genetic diversity and association mapping of morphine content and agronomic traits in Turkish opium poppy (Papaver somniferum) germplasm

“…These results indicate that the landraces in this study are not good material for improvement of stigma number. Bhandari (1990) suggested that landraces with more stigmas should be selected for morphine content improvement in opium poppy breeding and it was later shown that stigma number is strongly correlated with morphine content (Trivedi et al 2006). However, no correlation was seen in the current work.…”