The Future of Climate Resilience in Wheat

As the most widely cultivated crop globally - providing 20% of all human calories and protein - there is an urgent need to increase wheat’s resilience to harsher climates [1]. The risk of simultaneous crop failures due to heat and/or drought in global “breadbaskets” has risen and is projected to rise further [2-4]. Severe water scarcity events are predicted for up to 60% of the world’s wheat-growing areas by the end of this century [5]. Furthermore, for each 1°C increase in average seasonal temperature, it is predicted that wheat yields will decrease by 6% on average globally, and much more in some already marginal environments where wheat is a traditional staple food [6,7]. At the current rate of yield gain, wheat production is predicted to fall well short of future demand due to population growth alone. Emerging environmental threats only make the challenge harder. On top of this, demand by consumers, farmers and the food industry is predicted to increase due to wheat’s high grain-protein content relative to other cereals, wide growing range and adaptability to most environmental stresses. Since farmer adoption of improved cultivars is a critical part of adaptation [8], new and more targeted breeding efforts are needed to ensure that wheat's climate resilience is maximized [9-11]. This article briefly outlines research that has been conducted and current research needs to develop climate resilient wheat.

Factors influencing adoption of improved cultivars of macadamia (Macadamia spp.) among small-scale farmers in Embu County, Kenya

The study investigated the factors influencing adoption of improved cultivars of macadamia (Macadamia spp.) among small-scale farmers in Embu County, Kenya. Data was collected from a sample of 384 small-scale farmers obtained through multistage sampling procedure in ten sub-locations. Binary Logit model was used to determine the effect of selected institutional and socio-economic factors on adoption of improved cultivars of macadamia. The results revealed that education level (wald=26.160), access to extension services (wald=6.246) and farm size (wald=4.271) had significant positive influence on adoption of improved cultivars of macadamia while age of the farmer (wald=5.235) and market distance (wald=5.519) had a negative influence on the same. There is need to encourage the youth to embrace macadamia farming and to develop smart marketing strategies to promote adoption of improved cultivars.

Field Phenomics: Will It Enable Crop Improvement?

Field phenomics has been identified as a promising enabling technology to assist plant breeders with the development of improved cultivars for farmers. Yet, despite much investment, there are few examples demonstrating the application of phenomics within a plant breeding program. We review recent progress in field phenomics and highlight the importance of targeting breeders’ needs, rather than perceived technology needs, through developing and enhancing partnerships between phenomics researchers and plant breeders.

Transgenic and genome-edited fruits: background, constraints, benefits, and commercial opportunities

Breeding has been used successfully for many years in the fruit industry, giving rise to most of today’s commercial fruit cultivars. More recently, new molecular breeding techniques have addressed some of the constraints of conventional breeding. However, the development and commercial introduction of such novel fruits has been slow and limited with only five genetically engineered fruits currently produced as commercial varieties—virus-resistant papaya and squash were commercialized 25 years ago, whereas insect-resistant eggplant, non-browning apple, and pink-fleshed pineapple have been approved for commercialization within the last 6 years and production continues to increase every year. Advances in molecular genetics, particularly the new wave of genome editing technologies, provide opportunities to develop new fruit cultivars more rapidly. Our review, emphasizes the socioeconomic impact of current commercial fruit cultivars developed by genetic engineering and the potential impact of genome editing on the development of improved cultivars at an accelerated rate.

Determinants of adoption and intensity of improved faba bean cultivars in the central highlands of Ethiopia: a double-hurdle approach

Background Faba bean (Vicia faba. L) is the most important pulse crop both in area coverage and volume of annual production in Ethiopia. However, productivity in terms of yield in Ethiopia is still far below its potential. One important reason is that farmers are largely dependent on their local landraces. Despite the release of about 34 improved faba bean cultivars, farmers’ use of certified improved seeds is very low. This study, therefore, aimed to generate useful information on farmers’ adoption of improved faba bean cultivars by identifying factors that determine a farmer’s decision to use improved cultivars. Methods A multi-stage sampling technique was followed to select sample households. A cross-sectional household survey was used to collect data from 168 households that were randomly selected. Moreover, focus group discussions and key informant interviews were conducted. For data analysis, the Double-hurdle econometric model was employed. Results The results revealed that the majority, i.e., 77% of rural households depended on their local landraces. The adoption rate of improved faba bean seed at the household level was 23% which is very low. This low adoption rate was mainly due to a lack of access to improved seed and a lack of awareness about the improved cultivars. The results suggest that the decisions to adopt the improved cultivars and how much land to be covered appear to be explained by different processes. The double-hurdle econometric model result further revealed that while a farmer’s adoption decision is influenced by family size, farmers’ awareness about the existing improved cultivars, and extension contact, the intensity of adoption is determined by livestock holding and access to market information. Conclusion The result showed that most of the rural households were largely dependent on their local faba bean landraces which result in low yields at harvest. Therefore, it is suggested that the promotion of improved faba bean cultivars and improve farmers’ access to extension service and timely market information are the most decisive factors to be emphasized to improve the adoption of improved cultivars.

On-farm assessment of selected dual-purpose groundnut (Arachis hypogae) cultivars for food and feed

Ten field trials were conducted on farmers' fields in five villages in sub humid environment of northern Nigeria during the 1998 and 1999 cropping seasons to test the performances of improved groundnut cultivars for forage and seed production. Farmers' preferences and reasons for preference of the cultivars were also assessed. All the selected (improved) cultivars out yielded the local (control) cultivar. Forage, pod and seed yields were greater for cultivar M343-801A, followed by cultivar 88-801 and then cultivar M516-791 in that order. With the exception of Ca concentration, other nutritive value indices measured, showed sufficient concentrations for livestock production during the critical periods of low quality and scarce forage materials.

Dynamics of Race Structures of Pyricularia oryzae Populations Across 18 Seasons in Guangdong Province, China

Rice blast, caused by Pyricularia oryzae, is one of the most damaging fungal diseases affecting rice. Understanding how the pathogen’s race structure varies over time supports the efforts of rice breeders to develop improved cultivars. Here, the race structure of P. oryzae in Guangdong province, China, where rice is cropped twice per year, was assessed over 18 seasons from 1999 through 2008. The analysis was based on the reactions of a panel of seven differential Chinese cultivars to inoculation with a set of 1,248 isolates of P. oryzae in the province. The “total race frequency” parameter ranged from 14.7 to 39.7%, and the “race diversity index” ranged from 0.63 to 0.93. Twelve (ZA63, ZA31, ZA29, ZA21, ZA13, ZA9, ZB30, ZB17, ZB8, ZB2, ZC14, and ZC8) and two (ZD8 and ZD3) races were recognized as specific to indica and japonica rice types, respectively. Of the 59 distinct races identified, only two indica type races (ZC13 and ZC15) were identified as population-common, and nine indica type races (ZB1, ZB5, ZB6, ZB7, ZB13, ZB15, ZC5, ZC13, and ZC15) and one japonica type race (ZG1) were deemed to be population-dominant; the “total top two race isolate frequency” parameter ranged from 29.8 to 74.5%. On the host side, dynamics of resistance structures of the differential set were divided into three patterns: Both Tetep and Kanto 51 expressed the highest and most stable resistance, both Sifeng 43 and Lijiangxintuanheigu conveyed much lower and unstable resistance, and Zhenlong 13, Dongnong 363, and Heijiang 18 performed intermediate and seasonally dynamic resistance. Three interesting points distinguishing race structures of P. oryzae populations in southern and northeastern China were also discussed. [Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

WINTER BREAD WHEAT (TRITICUM AESTIVUM L.): WINTER HARDINESS OF ACCESSIONS IN THE ENVIRONMENTS OF THE NORTHWESTERN AND CENTRAL BLACK EARTH REGIONS OF RUSSIA

This publication presents the results of a field assessment of 225 winter bread wheat accessions from the VIR collection for their winter hardiness in the environments of the Northwestern (Town of Pushkin, 2007/2008, 2008/2009 and 2013/2014) and Central Black Earth (Yekaterinino Settlem., 2007/2008 and 2008/2009) Regions of the Russian Federation. The tested accessions included landraces and old improved varieties, earlier identified as sources of winter hardiness, as well as modern improved cultivars and lines, added to the VIR collection from 1990 through 2006. For reference purposes, along with the wintering data, information on biological and agronomic traits is given for the tested accessions. The presented data will be of interest to plant breeders and other experts working with winter bread wheat.

Assessment of Genetic Diversity in Traditional Landraces and Improved Cultivars of Rice

Background: Rice is the staple food for more than half of the world's population. Rice cultivation needs expansion to meet the increasing food demands across the globe. Genetic diversity is desired for crop breeding because it serves as the backbone for improving cultivars. The process of domestication and modern plant breeding technologies applied to rice has contributed to the erosion of genetic diversity. Current breeding programs have extensively shaped the genetic diversity of elite rice cultivars to no small extent. Results: We explored the genetic diversity of traditional landraces and improved cultivars by inspecting the whole genome SNP markers of 20 rice accessions. We found a higher number of genetic variations (76.70%) and observed heterozygosity (0.024) in landraces than improved cultivars. The principal component analysis also revealed the higher genetic diversity among the landraces. While population structure based on the phylogenetic tree suggested the population's structure according to rice subspecies. The genetic diversity parameter, FST, was applied to estimate the genetic differentiation of rice, which revealed week genetic differentiation (0.121) and nucleotide diversity (0.314) in modern rice cultivars. Genome-wide genetic differentiation (FST) analysis identified the two domesticated genes: Kala4 (pericarp color) and Ghd7 (heading date), and eight improvement genes: Sd1, Ghd8, GW2, NRT1.1b, GW6a, and Hd3a, that coincide with the candidate selective sweeps. Inbreeding depression (0.68617) among the modern cultivars suggests no genetic gain in future breeding efforts and compels exotic material utilization in the breeding programs. Conclusion: These findings demonstrate that modern cultivars have a narrow genetic base compared to landraces. Therefore, exploring the genome of landraces at a large scale to identify the genes responsible for stability and adaptation to abiotic stresses can help design varieties that can survive vulnerable climates.