GGE Biplot Analysis to Explore the Adaption Potential of Italian Common Wheat Genotypes

Given the substantial variation in global wheat yield, insufficient research in cultivar selection for climate change, and the lack of suitable germplasm in sustainable agroecosystems, there is a requisite for soft wheat genotypes, with stable grain yield as well as quality parameters. The present study was aimed at genotype evaluation (GGE biplot for “mean performance versus stability”) not only for yield, but also for technological, phytosanitary and functional quality parameters of 24 Triticum aestivum L. genotypes (eight landraces, old and modern varieties, respectively) within a single organic farm location (Argelato, Emilia-Romagna, Italy) over three consecutive years. Overall, high yield stability was shown for the landraces and old varieties. In particular, the landraces Piave and Gamba di Ferro, as well as the old variety Verna, showed high stability with above-average means for numerous quality parameters of interest. Additionally, relative stability combined with above-average mean for quality parameters was also demonstrated for the high-yielding Gentil Bianco and Guà 113. Aside from Verna, these “unrecognized” resilient genotypes were also shown to meet the requisites for suitable germplasm in sustainable agroecosystems. Future potential utilization of these more stable landraces in addressing climate change would also ultimately facilitate the survival of valuable genetic resources.

Growing cotton in China.

This chapter focuses on the current status of cotton production in China and the genetic improvement and use of Bt transgenic cotton cultivars in the country. Some major insect pests, weeds and diseases of cotton in the country are presented and the efficacy of various methods used in their management are highlighted. Some information on the cultivar selection, cultivation methods, harvesting technologies and fibre quality characteristics of cotton in the country are also discussed.

Socioeconomic Challenges of California Strawberry Production and Disease Resistant Cultivars

Strawberries are the 4th highest grossing crop in California and supply 90% of US strawberries. But the industry's long reliance on the use of chemical fumigants to control soil disease, nematodes and weeds is being threatened by increased regulation of these fumigants, leading to urgent efforts to develop and test non-chemical alternatives to fumigation, such as disease resistant cultivars. Many of these technologies are promising ecologically, but making them economically viable for growers is more challenging, especially in light of the socioeconomic context of strawberry production in California that has created a state of lock-in for a sustainability transition. This paper discusses how the challenges of land prices, labor shortages, marketing standards, and low prices bear on cultivar selection. Based on qualitative interviews, we corroborate that strawberry growers operate under significant socioeconomic constraints in California, many of which are beyond their control. In addition, we find that most growers see high-yielding varieties as crucial to their economic viability with regard to land, labor, and marketing intermediaries and yet recognize that the focus on individual farm productivity works at cross purposes to the problem of poor prices. Disease resistant varieties do not at face value address the concerns voiced by most growers. Our findings suggest, however, that if some of the other pressures were exogenously mitigated, growers might be more inclined to experiment with and adopt disease resistant varieties, in combination with other approaches. The most promising policy avenues seem to therefore lie with support of grower revenues.

Whole-Genome Sequencing on 220 Alfalfa (Medicago sativa L.) Accessions Identified Loci Associated with Fall Dormancy

Fall dormancy (FD) is one of the most important traits of alfalfa (Medicago sativa) for cultivar selection to overcome winter damage. Regrowth plant height following autumn clipping is an indirect way to evaluate FD. Although transcriptomics, proteomics analysis, and QTL mapping have revealed some important genes correlated with FD, the genetic architecture of this trait is still unclear. There are no applicable genes or markers for selection, which hinders progress in the genetic research and molecular breeding for the trait. We conducted whole-genome sequencing (WGS) on 220 alfalfa accessions at 10x depth. Among the 875,023 SNPs, seven of them were associated with FD using genome-wide association study (GWAS). One SNP located on chromosome 6 is in linkage disequilibrium with dehydration-responsive element-binding protein 1C (DREB1C). Furthermore, seven DREB genes are clustered in this region, one of which has previously been shown to enhance freezing tolerance in the model plant Medicago truncatula. The candidate genes uncovered by our research will benefit the transgenic and CRISPR-Cas9 research of FD in alfalfa. This gene will also be useful for marker development and assisted selection of FD for alfalfa.

Sod Tensile Strength, Handling Quality, and Their Interrelationship for 39 Bermudagrasses

Suitable tensile strength is essential for sod harvest, transport, and installation. Thirty-nine bermudagrass (Cynodon sp.) entries were evaluated for sod handling quality (SHQ) and sod tensile strength (STS) during 2014–15. The SHQ (a discontinuous qualitative parameter) was evaluated using a 1 to 5 scale with 1 = complete pad separation during handling and 5 = no cracking or separation in the sod pad with excellent quality. The STS (a quantitative parameter) was determined using the force required to shear/separate the sod pad. Sod harvests were conducted at 14, 22, and 24 months after planting (MAP). The entry, harvest date, and their interaction affected STS and SHQ. Entries OKC 1302 and 12-TSB-1 had greater STS than ‘Patriot’ but less STS than ‘Latitude 36’, ‘Tifway’, ‘Astro’, and ‘TifGrand’. The seeded entry PST-R6T9S had the lowest STS and SHQ. The overall mean STS and SHQ were lowest at 22 MAP, which could be attributed to the slow recovery of the entries after Winter 2014. A strong positive correlation (r = 0.92) between STS and SHQ suggests that SHQ can be used as a rapid field method to estimate suitability for sod harvest. A predictive linear relationship between overall STS and overall SHQ (r2 = 0.85) found predicted STS values of 8.5, 22.6, 36.8, and 51.0 kg⋅dm–2 for overall mean SHQ ratings of 2, 3, 4, and 5, respectively. The results of this work will help sod producers in cultivar selection and will aid breeders in making commercialization decisions.

Climate Change Impacts on Plant Phenology: Grapevine (Vitis vinifera) Bud Break in Wintertime in Southern Italy

The effects of global warming on plants are not limited to the exacerbation of summer stresses; they could also induce dormancy dysfunctions. In January 2020, a bud break was observed in an old poly-varietal vineyard. Meteorological data elaboration of the 1951–2020 period confirmed the general climatic warming of the area and highlighted the particular high temperatures of the last winter. Phenological records appeared to be significantly correlated to wood hydration and starch reserve consumption, demonstrating a systemic response of the plant to the warm conditions. The eight cultivars, identified by single-nucleotide polymorphism (SNP) profiles and ampelographic description, grown in this vineyard showed different behaviors. Among them, the neglected Sprino, Baresana, Bianco Palmento, and Uva Gerusalemme, as well as the interspecific hybrid Seyve Villard 12.375, appeared to be the most interesting. Among the adaptation strategies to climate changes, the cultivar selection should be considered a priority, as it reduces the inputs required for the plant management over the entire life cycle of the vineyard. Hot Mediterranean areas, such as Salento, are a battlefront against the climate change impacts, and, thus, they represent a precious source of biodiversity for viticulture.

Rice cultivar selection in an agroforestry system through GGE-biplot and EBLUP

Alam T, Suryanto P, Supriyanta, Basunanda P, Wulandari RA, Kastono D, Widyawan MH, Nurmansyah, Taryono. 2021. Rice cultivar selection in an agroforestry system through GGE-biplot and EBLUP. Biodiversitas 22: 4750-4757. Genotype-by-environment interaction (GEI) causes differences in the productivity of rice cultivars in agroforestry systems. For this reason, the stability of rice cultivars is an important aspect that should be considered before a cultivar is recommended to farmers. Superior genotypes and ideal environments are commonly identified using two statistical models, namely, genotype–genotype-by-environment biplot (GGE-biplot) and empirical best linear unbiased prediction (EBLUP). In this study, 15 rice cultivars were evaluated in terms of their productivity and stability in three soil types (Lithic Haplusterts, Ustic Epiaquerts, and Vertic Haplustalfs) in an agroforestry system with kayu putih (Melaleuca cajuputi) in 2019 and 2020 at the Menggoran Forest Resort, Playen Forest Section, Yogyakarta Forest Management District, Indonesia. The cultivars were treated as random effects to select and obtain the EBLUP of the best cultivars in each soil type. The EBLUP revealed that Situ Patenggang showed the highest yields of 4.887 and 5.456 tons ha?1 in Lithic Haplusterts and Vertic Haplustalfs, respectively. GM 28 exhibited the highest yield of 6.492 tons ha?1 in Ustic Epiaquerts. Ciherang, GM 2, GM 8, GM 11, GM 28, Inpari 6 Jete, Inpari 33, IR-64, and Way Apo Buru were classified as stable and fairly stable cultivars, whereas the other cultivars were unstable. Therefore, rice cultivars with high yields in specific soil types should be selected.

Pennsylvania State University Statewide Cultivar Evaluation Program Model

Cultivar selection is an important managerial task for commercial farmers. Numerous available options provide marketing opportunities for farmers; however, they can also make cultivar selection time-consuming. For the past 13 years, a team of Penn State Extension educators and university faculty has implemented a new model to evaluate cultivars for key vegetable crops to assist farmers. Our approach started by building relationships within the vegetable industry with farmers, seed company representatives, and farmer-driven organizations who support our program with funding and gift-in-kind donations. We also added rigor to cultivar evaluations by conducting trials of key vegetable crops over 2 years at three locations. The results were used to develop cultivar recommendations, which were disseminated through various face-to-face and distance Extension avenues. The results were also published in refereed journals. The combination of funding, Extension products, and refereed articles led to university support. A drawback to our approach was the difficulty implementing uniform production methods at three experimental sites. The input of a statistical consultant assisted with overcoming this drawback. This model also required the use of strategies common to successful teams. Our methods are described here for those who desire to build a similar program.

Improving Snapdragon Cut Flower Production through High Tunnel Season Extension, Transplant Timing, and Cultivar Selection

The demand for locally grown, specialty cut flowers is increasing and now includes nontraditional regions for production, such as the U.S. Intermountain West. The objective of this study was to evaluate snapdragon (Antirrhinum majus L.) as a cool season, cut flower crop in northern Utah, where the high elevation and semiarid climate result in a short growing season with strong daily temperature fluctuations. High tunnel and field production methods were trialed in North Logan, UT (41.77°N, 111.81°W, 1382 m elevation) with cultivars ‘Chantilly’, ‘Potomac’, and ‘Rocket’ in 2018 and 2019. Each year, five to six transplant timings at 3-week intervals were tested, beginning in early February in high tunnels and ending in late May in an unprotected field. Stems were harvested and graded according to quality and stem length. High tunnels advanced production by 5 to 8 weeks, whereas field harvests continued beyond the high tunnel harvests by 2 to 8 weeks. High tunnels yielded 103 to 110 total stems per m2 (65% to 89% marketability), whereas field yields were 111 to 162 total stems per m2 (34% to 58% marketability). Overall, production was the greatest with March transplant timings in the high tunnels and mid-April transplant timings in the field. ‘Chantilly’ consistently bloomed the earliest on 4 and 6 May each year, ‘Potomac’ had the highest percentage of long stem lengths, and ‘Rocket’ extended marketable stem production through July in high tunnels. Selecting optimal transplant dates in the high tunnel and field based on cultivar bloom timing maximizes marketable yields and results in a harvest window lasting 4.5 months.