**9. Screening varieties**

Varietal difference with regard to resistance for fruit and shoot borer was observed in brinjal. Choudhary *et al*. [26] screened eight varieties against *L. Orbonalis.* The order of susceptibility ofbrinjal varieties was recorded as Pant Samrat< Pant Rituraj<Manjarigota<Pusa Purple Long < Pant Brinjal-5 < Kavach< MHB-80 < BR-112 during 2014–2015 and 2015–2016, respectively. In another study, Amit et al. [27] screened twenty five brinjal varieties against brinjal shoot and fruit borer and red spider mite and IBH-3, IBL-116, Rajindra brinjal, KS-356, JB-24, JBH-8, IBH-02 andCHBR-1 were found tolerant. The research carried out at RARS, Jamalpur, Bangladesh showed that, the brinjal varieties Jumki-1 and Jumki-2 were highly resistant (HR), Islampuri-3, BL-34 and Muktakeshi were fairly resistant (FR), Singnath long and Singnath-4 were tolerant to brinjal shoot and fruit borer [28].

Similarly, in okra Rehman *et al*. [29] screened four varieties (SabzPari, SadaBahar, PusaSawani, Arka Anamika) and those varieties showed some degree of resistance against sucking insect pests. Okra variety Sada Bahar was less infested with jassid (1.30/leaf) and whitefly (5.36/leaf) compared to other tested varieties and resulted in maximum yield (1529.62 kg/ha). Number of fruits pods per plant was found non significantly different on all the tested okra varieties.

In another experiment, Jackson and Bohac [30] evaluated sweet potato accessions by using bio assay techniques using the adults of banded cucumber beetle and spotted cucumber beetle. A single beetle was placed on a piece of sweetpotato peel that was embedded periderm-side up in plaster in a petridish. Feeding and longevity of insects on sweet potato genotypes were evaluated. Durability of feeding with respect to banded cucumber beetles on sweet potato peels ranged from 12 d for the most-resistant genotype to 123 d for a susceptible control cultivar (SC1149–19). The feeding longevity of spotted cucumber beetles was slightly shorter than banded cucumber beetles. For the highly resistant genotypes, both the species exhibited a significant delay in feeding initiation, and most beetles died before they had fed the sweet potato. Thus it was evident that both antibiosis and non preference (antixenosis) are important mechanisms of resistance in sweetpotato genotypes.

Seventy seven eggplant genotypes were tested for resistance to *root*-knot nematode by classical testing. As a result it was determined that P29 and P52 genotypes were resistant.*Ditylenchus destructor* and *Ditylenchus dipsaci* are economically important plant-parasitic nematodes, affecting potato production mostly in temperate climates. Mwaura and Vidal [31] screened 25 potato varieties for resistance to and tolerance for *D. destructor* and *D. dipsaci* infections. Reproduction factor (RF) and relative susceptibility (RS) were used to evaluate resistance, Based on Reproduction factor, sixteen varieties were assessed as susceptible (S) and five were identified as resistant (R) to *D.* destructor. The varieties Innovator, Aveka and Spunta were identified as resistant to *Ditylenchus dipsaci*. The highly susceptible one for *D. destructor* and *D. dipsaci* in both experiments was Desiree and was used as the standard susceptible control variety for the calculation of RS. An 1–9 scale was used to assess and classify the potato varieties based on level of resistance to *D. destructor* and *D. dipsaci*, where 9 indicated the highest level of resistance. Among the varieties screened six had significantly lower relative susceptibility (RS) to *D. dipsaci* than the standard susceptible control. Few varieties were also observed to be tolerant to both the nematodes. The suitable indices for resistance and tolerance determination were relative susceptibility (RS) and external potato tuber damage.

Nayak and Pandey [32], screened one hundred fifty brinjal varieties/cultivars against root-knot nematode, only twenty varieties have shown resistant reaction with

#### *Breeding Approaches for Biotic Stress Resistance in Vegetables DOI: http://dx.doi.org/10.5772/intechopen.94983*

least gall index (1.1 to 2.0) viz., Gachhabaigan, Azadkranti, Kantabaigen, Athagara Local, Kamaghara local, Solanum indicum, PBR 129–5, ARU-1, BB1–3, BB 45-C, BB-49, KS-224, Utkal madhuri, BR-112, LB-13, LB-25, LB-28, LB-30, LB-44, LB-55.

Akhter and Khan [33], screened thirty brinjal varieties for their resistance/ susceptibility to root-knot nematode (*Meloidogyne incognita* race-1) infestation. Out of 30 brinjal varieties, eighteen varieties viz., Black Beauty, Brinjal 1 hybrid, Brinjal No.38, Chamak, Govinda, Green round, Nagina, Nav Kiran, Neel Kamal, Nishant, P.K-123, Prabha Kiran, Prasad, Sukhda, Surya Kiran, i9Utkal, VNR-51 and VNR-60 were highly susceptible, seven varieties (Brinjal Advance, Brinjal BSS1013, Green long, Harshit, Prapti, Shamli and Ujjwal) were susceptible, two varieties (Mahy 112 and Mahy Ruby) were tolerant, two varieties (Hybrid green and JK Kajal) were moderately resistant and only one variety Mahy 80 was resistant against *Meloidogyne incognita* race-1. Mahy 80 variety was ported to be resistant against root-knot nematode, *M. incognita* race-1 for the first time.
