The major wheat-producing countries have heterogeneous and fragile agro climatic surroundings but frequently restraining wheat yield and quality losses are predominant under heat and drought prone agriculture exclusively when both stresses occur in blend, which looms the food security globally. However, many suggested examples are available in these countries for the mitigation of these two stresses by using different conventional and modern improvement and agronomic approaches. In addition to these approaches, morphological, physiological, anatomical, biochemical, phenological, and physiochemical vicissitudes, which trigged during these stresses, have also been elucidated. There complete deliberation in combination for wheat improvement is still a contest, but a win-win option is a holistic attitude in future.

The rust fungi especially emergence of new rust races has serious threat to global wheat production. This is mainly due to the widespread use of race-specific seedling resistance genes and evolution of new virulence races like Yr9, Yr27, and Sr31. Several quantitative disease resistance (QDR) or durable resistance genes i.e. Lr34/Yr18/Pm38/Sr57, Lr46/Yr29/Pm39/Sr58, Lr67/Yr46, Lr68 providing resistance to rust diseases at either high or low temperatures have been identified. But, changing climatic conditions affect the level of resistance in cultivars, as at high temperature Lr34/Yr18 genes which confer durable resistance in wheat become less effective and at low temperature it provides high resistance. While in contrast, yellow rust resistance genes; Yr36 and Yr39 confer resistance at high temperature and later growth stages. This review provides a detailed discussion on, the different aspects of climate change that how it affect host resistance and pathogenic variability and its sustainable control by developing cultivars with high level durable resistance.

Epidemics of leaf, stripe and stem rusts on wheat have induced significant losses in the past during the early nineteenth century and have destroying role in reducing product yield bringing about socioeconomic variability worldwide. The old tall varieties with qualitative resistance couldn't continue for longer period because of the advancement of new virulent pathogen races. But varieties like Yaqui-50, Lyalpur-73, and Lerma Rojo-64 were released during early period of green revolution, still linked with durable resistance to stripe, leaf and stem rust. Advancement of new rust races like virulence's Yr27 and Yr9 followed by the appearance of Ug99 and its mutants lead the breeders to review their breeding plan. Breeders are presently relying upon to gather minor genes and their use in grouping with major genes to develop rust resistance in wheat varieties. The minor genes, Lr46/Yr29, Lr34/Yr18, Sr2/Yr30, are being broken in wheat breeding at CIMMYT and different region. The germplasm with this kind of resistance have shown existence stability over space and time. At Ayub Agriculture Research Institute, Faisalabad the home of green revolution in Pakistan, this approach has been established since1994-95. The durable resistance assortments were crossed in a top cross/back cross technique and the segregating populations were improved by adopting mass strategy, which brought about the advancement of material having preferred yield and rust resistance over the pre-exiting assortments (e.g., Inqlab-91, MH-97). Five varieties, Shafaq-06, Lasani-08, AARI-11, Millat-11 and Galaxy-13 from these crosses have been approved for general cultivation. Essentially, the material developed and circulated by CIMMYT, Mexico having this sort of resistance is being worldwide adopted. The simple sequence repeat markers (SSR) for above mentioned durable genes are accessible and can be used in early selection of superior varieties.

Abstract:A study was conducted on reducing the yield loss of wheat due to leaf rust caused by Puccinia triticina with foliar application of fungicides during the 2014-2015 and 2015-2016 growing seasons at the Wheat Research Institute in Faisalabad, Pakistan. Three fungicides: Folicur (tebuconazole) at 300 mL/ha, Nativo (tebuconazole + trifloxystrobin) at 300 g/ha and Tilt (propiconazole) at 500 mL/ha were applied single or two times to Morocco and Sehar-06 wheat varieties used in the trial. The trial plots were first sprayed at the Zadok's scale (ZS) 3 stage and second sprayed between ZS 4.3 and 5.4 stages. The greenness of the trial crop was measured using GreenSeeker. Foliar application of fungicides significantly reduced the loss of grain yield and 1,000-grain weight (TGW) of wheat due to leaf rust in comparison to the control without fungicides application. Of the three fungicides, two times spray of Nativo reduced the grain yield loss of leaf rust susceptible mega wheat variety Sehar-06 by 45%-56% and the loss of TGW by 42%, also giving the highest marginal return in the trial. Single application of Nativo was equally effective as two times spray of Folicur in reducing the loss of wheat grain yield. Two times spray of Folicur was found to be the second choice of fungicide for reducing the yield loss of wheat. The research identified suitable fungicides for reducing the yield loss of wheat due to leaf rust and also generated important scientific knowledge required to manage a sudden outbreak of leaf rust to ensure food security.