In addition to the well-known Fusarium oxysporum f.sp. lycopersici, several other Fusarium species are known to cause extensive worldwide crop losses in tomatoes. Prevalence and identities of Fusarium species infecting tomatoes in Northwest Pakistan is currently not known. In this study, we surveyed and characterized Fusarium species associated with symptomatic tomatoes in Northwest Pakistan using morphological and molecular analyses. Pathogenicity tests revealed varying degrees of virulence with some Fusarium sp. causing severe disease symptoms whereas others displaying mild symptoms. Molecular identification based on Internal Transcribed Spacer (ITS) region and TEF-1α gene sequencing classified all isolates into four major species with a majority (68.9%) belonging to Fusarium incarnatum-equiseti species complex (FIESC), followed by F. graminearum (20.7%), F. acuminatum (6.8%), and F. solani (6.8%). ISSR analyses revealed substantial genetic variability among all the Fusarium population infecting tomatoes. Genetic distance between populations from the central region and the type strain F.o. f.sp. lycopersici from Florida was the highest (0.3662), whereas between the south and central region was the lowest (0.0298), which showed that genetic exchange is negatively effected by distance. High genetic variability suggests that these Fusarium species have the potential to become a major production constraint for tomato growers. Findings in this report would greatly facilitate identification of Fusarium species in developing countries and would provide groundwork for devising and implementing disease management measures for minimizing losses caused by Fusarium species in tomatoes.

Wheat streak mosaic virus (WSMV), vectored by Wheat curl mite, has been of great economic importance in the Great Plains of the United States and Canada. Recently, the virus has been identified in Australia, where it has spread quickly to all major wheat growing areas. The difficulties in finding adequate natural resistance in wheat prompted us to develop transgenic resistance based on RNA interference (RNAi). An RNAi construct was designed to target the nuclear inclusion protein ‘a’ (NIa) gene of WSMV. Wheat was stably cotransformed with two plasmids: pStargate-NIa expressing hairpin RNA (hpRNA) including WSMV sequence and pCMneoSTLS2 with the nptII selectable marker. When T₁ progeny were assayed against WSMV, ten of sixteen families showed complete resistance in transgenic segregants. The resistance was classified as immunity by four criteria: no disease symptoms were produced; ELISA readings were as in uninoculated plants; viral sequences could not be detected by RT-PCR from leaf extracts; and leaf extracts failed to give infections in susceptible plants when used in test-inoculation experiments. Southern blot hybridization analysis indicated hpRNA transgene integrated into the wheat genome. Moreover, accumulation of small RNAs derived from the hpRNA transgene sequence positively correlated with immunity. We also showed that the selectable marker gene nptII segregated independently of the hpRNA transgene in some transgenics, and therefore demonstrated that it is possible using these techniques, to produce marker-free WSMV immune transgenic plants. This is the first report of immunity in wheat to WSMV using a spliceable intron hpRNA strategy.

Wheat streak mosaic virus (WSMV) has been newly documented in Australia. The vulnerability of contemporary Australian elite wheat germplasm prompted a survey for effective resistance against an Australian isolate, WSMV‐ACT. This study confirms the effectiveness of previously reported sources of resistance and shows that new sources of resistance also confer protection. The resistance derived from Thinopyrum intermedium ( Wsm1 ) as a 4D translocation and a new 4A translocation, and two bread wheat resistances, Wsm2 and the new source c2652, were effective against WSMV‐ACT in glasshouse experiments. Wsm1 was effective at lower temperatures but ineffective above 20°C, a temperature sensitivity shared with many of the derivatives of Wsm2 except for one new selection which was effective at 26°C. True wheats c2652 and Wsm2 selection CA745, and amphiploids Zhong1, Zhong2, Zhong4, Zhong5, TAF46, Summer1, Ot38 and OK7211542 were uniformly resistant at 20, 25 and 28°C. New sources of resistance were identified in a Th. scirpeum ‐wheat amphiploid, B84‐994, and in chromosome addition lines Z2, Z6 and TAi27, derived from wheat‐ Th. intermedium partial amphiploids. Several new, tightly linked SSR, RAPD and EST‐ILP PCR markers were developed for tracking the various Th. intermedium translocations associated with Wsm1, including the smaller translocations on wheat chromosome 4AS and 4DS. Three markers for the 4A‐ Wsm1 translocation were validated on a segregating breeding population.

Lactobacillus plantarum strains have been extensively used in food processing and preservation. L. plantarum also has the potential to convert polyunsaturated fatty acids, e.g. linoleic acid (LA) into bioactive and less toxic fatty acid metabolites. The objective of this study was to assess the capability of probiotic L. plantarum 13-3 to convert Linoleic Acid (LA) to different fatty acid metabolites in the medium supplemented with differential concentrations of LA, and the relevant reactions were characterized by in silico calculation. L. plantarum 13-3 was grown in MRS medium containing LA from 1% to 10%, and the fatty acid metabolites formed in the medium were identified and quantitated by GC-MS and in silico studies were done to confirm the enzymatic reactions involved in its conversion. The results showed that L. plantarum 13-3 could convert LA at different concentrations to 5 different fatty acid metabolites i.e, (Z)-Ethyl heptadec-9-enoate, 9,12-Octadecadienoic acid (Z, Z), methyl ester, Octadec-9-enoic acid, cis-11,14-Eicosadienoic acid, methyl ester and (Z)-18-Octadec-9-enolide. Among these metabolites, the formation of an long chain fatty acid Octadec-9-enoic Acid, also known as 18:1, N-9 or Delta(9)-Octadecenoic acid, is classified as a member of the Long-chain fatty acids in media supplemented with 4% to 10% LA, is being reported for the first time. Putative candidate enzymes involved in biotransformation of LA into fatty acid metabolites were identified in whole genome of L. plantarum 13-3, sequenced previously. In silico studies confirmed that several enzymes including the linoleate isomerase, acetoacetate decarboxylase and oxidoreductase may be involved in biotransformation of LA into fatty acid metabolites. These enzymes could effectively bind the LA molecule mainly by forming hydrogen bonding between the acidic groups of LA and the proline residues at the active sites of the enzymes validating the putative reacting partners.