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The objective of this paper was to measure resistance to Puccinia coronata f.sp. avenae (Pca) in a set of 63 previously uncharacterised new and historical oat cultivars representing 120 years of Polish oat breeding. The distinctiveness of the obsolete and modern gene pools led to the expectation that the earlier cultivars could be a valuable source of useful resistance genes discarded during subsequent breeding. The plant material was tested at the seedling stage using 14 Pca pathotypes and at the adult plant stage under natural infection conditions in 3 years of field observations. In all, 23 genotypes displayed an immune response to at least one Pca pathotype in the test at the seedling stage, however, most of them were susceptible to crown rust infection in the field. The most resistant, presenting immunity to 9 out of 14 P. coronata isolates, was Celer. The infection profile of this cultivar corresponded to the pattern of reference line Pc39. An allelism test confirmed that the resistance of both the Pc39 line and Celer is conditioned by either the same locus or by tightly linked genes. The infection analysis also demonstrated that some of the newest cultivars (Elegant, Komfort and Harnaś) showed a relatively high level of resistance in each year of field trials, despite being completely susceptible at the seedling stage. Further research will be required to evaluate the source, durability and suitability of this resistance. The study did not find any novel resistance to crown rust in the historic cultivars. However, results provide a new insight into adult plant stage resistance in Polish modern cultivars. The resistance of these cultivars is the result of many years of selection in breeding programs and provides an excellent base for future work. [ABSTRACT FROM AUTHOR]

Pure line breeding is a resource-intensive activity that takes 10 years or more to develop a new cultivar. In some crops, conducting off-season nurseries has significantly reduced the length of the breeding cycle. This approach could not be exploited in pigeonpea [Cajanus cajan (L.) Millsp.], because traditionally it has been a photoperiod-sensitive crop that requires long periods of darkness to induce flowering. However, the recent success of breeding early maturing photoperiod-insensitive genotypes has opened up the possibility of adopting 'speed breeding' techniques to enable rapid generation turnover. This paper outlines a speed breeding approach that integrates the use of immature seed germination for rapid generation advancement and a "single pod descent" method of breeding. To accelerate line development, while conserving genetic variability, the approach permits four generations per year and can fast-track field evaluation of resulting homozygous lines. Therefore, the breeding strategy conserves resources and has potential to deliver new early maturing cultivars within a substantially reduced timeframe of 4–5 years. [ABSTRACT FROM AUTHOR]

Cowpea ( Vigna unguiculata L. Walp.) is an important cash, food and nutritional security grain legume crop in the semi-arid regions of sub-Saharan Africa. However, its productivity is hampered by several biotic stress factors including numerous insect pests that infest and damage the crop at all its development stages in the field as well as during storage. Host plant resistance is an environmental-friendly, cost-effective and sustainable pest management option for minimizing the pests' incidence and severity. This review article aims at describing the major insect pests in cowpea and highlight key past and recent research findings in cowpea resistance to insect pests. It also provides in-depth knowledge in the host-plant resistance mechanisms in cowpea i.e. biophysical, biochemical and physiological factors that regulate the defense systems in the plant. Furthermore, the paper discusses the need for advanced investigation on the genetic basis of the plant defense systems and its application to the crop breeding program for developing new improved materials. The review would support the cowpea breeding program with the overall expectations of developing insect-resistant lines, reducing the input costs of insecticides while also enhancing cowpea productivity in sub-Saharan Africa. [ABSTRACT FROM AUTHOR]

Heat stress (HS) is a major threat to current and future crop production. Crop improvement for HS tolerance is a major tool for dealing with HS and crop wild relatives (CWR) offer the greatest variability for such improvement. Here, we evaluated the HS tolerance on four reproductive traits in cultivated and wild sunflower and tested for local adaptation to HS within the wild germplasm. Three cultivars and 23 wild populations (from native and invasive ranges) were grown in field experiments for 2 years. Flowering heads were covered with white (control) and black (HS) paper bags during seven consecutive days. Additionally, biogeographic tools were used to test for local adaptation. HS increased air temperature on black bags compared to the white ones by 9.4 °C on average and strongly decreased seed number and yield with smaller effects on head diameter and seed weight. We found large variability for HS tolerance, mainly in seed number and yield. The invasive group outperformed the cultivated and native groups in both years. Biogeographic analysis reveals a clinal variation in HS tolerance, populations from wetter (but not from warmer) environments were more tolerant to HS. In addition, the positive correlation observed between reproductive traits under control conditions and HS tolerance helps to explain the better performance of the invasive populations. We proposed the use of invasive populations for future sunflower improvements in HS tolerance and the adoption of biogeographic tools in another CWR species to identify HS tolerant populations. [ABSTRACT FROM AUTHOR]

Septoria tritici blotch (STB), caused by fungal agent Zymoseptoria tritici (previously known as Mycosphaerella graminicola) is a devastative foliar wheat diseases globally. Importance and potential threat of STB have been discussed historically and geographically. This paper reviews information on the Z. tritici—wheat pathosystem and proposes approaches to identify resistance genes and to advance in breeding for STB resistance. Screening of resistant lines/cultivars, QTL mapping analysis within genetic populations derived from crosses, detection of new resistance gene(s) and finally application of Stb gene carrier line/cultivar in crosses are the major stages of a practical wheat-breeding program against STB of wheat. Phenotyping and genotyping outputs on the top of each other should confirm each other, so it needs to expose a resistance gene carrier line/cultivar in the epidemic condition at seedling/adult plant stage to confirm resistance performance of detected gene(s) in the real condition. On the other word, detecting an associated QTL to resistance should not be considered as the end of investigation. Climate change resulted geographical disease pattern conversion where some diseases became more important in some area where they had not been serious in the past and vice versa. Hence, a reconsideration of wheat disease importance zone is necessary to predict regions where STB is and will be a limitation for wheat yield improvement. [ABSTRACT FROM AUTHOR]