Abstract
The reaction of four wheat RbcS RNAi mutants and wild type to the infection of M. incognita was investigated in a greenhouse pot experiment using plant growth parameters as well as nematode reproduction. Obtained results revealed that all estimated growth parameters of lines under study were reduced by M. incognita infection to various extents. RSS13.2 line showed the highest percentage of reduction of plant total fresh weight, length, and shoot dry weight. It did act as good host for root-knot nematode; therefore, it was classified as susceptible host. In addition, the lowest reduction percentage of fresh and dry weights was observed in RSS8.5 line although it showed high values for nematode development and reproduction parameters; therefore, it seemed to be as a tolerant host The maximum reduction in chlorophyll content was recorded in RSS7.6 line, whereas, the minimum was obtained from RSS11.5 line. It was evident that none of the five tested wheat lines was immune to Al incognita infection. The lowest numbers of second stage juveniles, galls, and egg-masses were observed in soil and on roots of RSS11.5 line although its plant growth was slightly affected; therefore, it is considered as partially resistant line. It could be concluded from the results of this study that, RNAi mutants of the RbcS were partially effective in suppressing root-knot nematode development. (C) 2019 Friends Science Publishers