Hybrid Cultivars Research Articles

Development of novel species-specific and genus-specific primers for the detection of Babaco Mosaic Virus (BabMV).

Babaco is a hybrid cultivar native to the Andean region of Ecuador and Colombia, commercially attractive for its fruit. Babaco production in Ecuador faces losses from plant pathogens like babaco mosaic virus (BabMV), an RNA virus that causes chlorosis, leaf mottling, and deformation. Phylogenetic studies link BabMV to papaya mosaic virus (PapMV), alternanthera mosaic virus, and senna mosaic virus. To address this threat, we developed novel species-specific primers to detect BabMV targeting a 165bp region of the coat protein (CP). Genus-specific primers were designed to validate the species-specific primers and attest their ability to discriminate between BabMV and its closest relatives. These primers targeted a 175bp fragment of the CP region. The most effective sets of primers were chosen for reverse transcription polymerase chain reaction (RT-PCR) and SYBR® Green-based quantitative reverse transcription polymerase chain reaction (RT-qPCR) in symptomatic and asymptomatic babaco plants. Among 28 plants tested, 25 were positive and 3 were negative for BabMV using species-specific and genus-specific primers in RT-PCR and RT-qPCR, while the PapMV positive control was detected with the genus-specific primers and was negative for the species-specific primers. These primers represent a valuable molecular tool for detecting BabMV, potentially enhancing crop management.

Differential Effects of Nitrogen and Phosphorus Fertilization Rates and Fertilizer Placement Methods on P Accumulations in Maize.

Crop production in Afghanistan suffers from limited phosphorus (P) availability, which severely hinders national agriculture sustainability. This study hypothesized that deep fertilizer placement could significantly enhance the uptake of immobile P and, thus, tissue P accumulation and crop yield. A two-year pot experiment growing two maize (Zea mays) hybrid cultivars (Xida-789 and Xida-211) was, therefore, conducted to test these hypotheses under three contrasting fertilizer placement methods (broadcast, side band, and deep band). In doing so, P concentrations in both maize tissues and soils were compared at 45, 60, and 115 days after sowing (DAS) under nine combinations of nitrogen (N) and P fertilizer rates (kg ha-1: N112P45, N112P60, N112P75, N150P45, N150P60, N150P75, N187P45, N187P60, N187P75). Results have shown that deep band placement significantly increased P uptake efficiency, leading to greater P concentration and accumulation in maize tissues compared to the other two fertilization methods. This improved P uptake was attributed to several factors associated with deep placement, including reduced P fixation, enhanced root access to P, and moisture availability for P uptake. Additionally, deep band placement combined with higher N application rates (N187 and N150) further enhanced plant P uptake by promoting P availability and utilization mechanisms. Deep band placement also resulted in significantly higher total soil P, Olsen-P, and P use efficiency than broadcast and side band methods, indicating a more efficient P fertilization strategy for maize that can improve growth and yield. This study also found positive correlations between P concentration in plant organs and soil Olsen-P, highlighting the importance of adequate soil P levels for optimal plant growth. Overall, our results have shown that deep band fertilizer placement emerged as a superior strategy for enhancing P uptake efficiency, utilization, and maize productivity compared to broadcast and side band placement. The outcome generated from the deep band fertilization by this greenhouse study can be recommended for field practices to optimize P fertilizer use and improve maize production while minimizing potential environmental P losses associated with broadcast fertilization.

Root growth dynamics of two southern highbush blueberry (V. corymbosum L. interspecific hybrids) cultivars in the Western Cape, South Africa

The objective of this research was to obtain a better understanding of the root growth dynamics of two southern highbush blueberry (SHB) cultivars, '8-–42′ 42′ and '9–02′, in the Western Cape, South Africa, southern hemisphere (SH). The number and length of new roots were measured from June 2020 to June 2021 in commercial orchards in the Hex River production area. Root production was similar between the cultivars and initially peaked at the onset of early winter, to coincide with flowering. A second peak occurred in mid-summer, approximately one month after fruit harvest and summer pruning (late November, SH) and continued until shoot growth declined in late autumn (early May, SH). Soil temperatures ranged between 11 and 20 °C during the first peak in root production and 17 and 31°C during the second peak, suggesting that new root production was controlled by the stage of plant development rather than soil temperature. This paper provides the first report on root development in SHB under the SH conditions and contributes towards implementing precision irrigation and fertigation strategies for evergreen systems.

Usefulness of alien sterilizing cytoplasms for the hybrid breeding of triticale (xTriticosecale Wittmack): preliminary results.

To be useful for cereal breeding, cytoplasmic male sterility (CMS) should express the complete sterility of maternal lines and the full restoration of the male fertility of F1 hybrids. The most reliable source of sterilizing cytoplasm for triticale is Triticum timopheevi; however, due to the low frequency of efficient non-restorer genotypes for this cytoplasm, new sources of CMS are needed. In this study, aside from T. timopheevi (T) cytoplasm, three alternative CMS sources were tested: Pampa (P) from Secale cereale L., Aegilops sharonensis (A), and Ae. ventricosa (V). The suitability of these cytoplasms for breeding was assessed based on the male fertility/sterility of F1 hybrids obtained through the manual pollination of CMS maternal lines with 36 triticale cultivars and breeding strains. About half of the hybrids with each type of cytoplasm were fully fertile and produced more than 30 grains per bagged spike. The highest percentage was found in hybrids with P cytoplasm (58.33%) and the lowest in hybrids with A cytoplasm (44.44%). Male sterility was observed in hybrids with P cytoplasm (16.67%) and A cytoplasm (16.67%) but not in hybrids with T or V cytoplasm. In terms of practical aspects, male sterility systems with P or A cytoplasm exhibit similarity in their ability to restore male fertility that differ from the T and V cytoplasms. Although all studied cytoplasms exhibited some disadvantages for breeding purposes, none should be definitively classified as unacceptable for future breeding programs regarding the development of triticale hybrid cultivars.

Analysis of Heterosis and Stability in Brinjal at Multi-locations of Gujarat for Yield and its Attributing Traits

Background: Brinjal is the important vegetable crop. The extensive use of heterosis in vegetable crops has led to the creation of numerous high-yielding hybrid cultivars. Newly developed hybrids should also be tested across environments to develop region specific hybrids or hybrid for all the regions. Methods: The purpose of the present experiment was to develop region-specific brinjal (Solanum melongena L.) hybrids through line ´ tester design and to gather information on heterosis and stability for fruit yield and associated characters at multiple locations of viz., Sardarkrushinagar, Jagudan and Bhiloda under the jurisdiction of S.D.A.U. in late rabi 2021–2022. Result: There were noticeable genetic differences in the material for the majority of the traits. Several crosses were identified which showed desirable heterosis for at least one yield component in individual and pooled over locations. Fruit yield per plant is the most important trait. Hybrid ‘ISD-006 × GOB-5’ showed the highest fruit yield and maximum standard heterosis for fruit yield per plant, fruit girth, fruit weight, total soluble solids and chlorophyll content index. The interaction of G × E was highly significant for the majority of characters suggesting the differential response of experimental material to the varied locations. Stability analysis suggested ‘ISD-006 × GAB-6’, ‘JDNB-16-1 × GOB-1’ and ‘ABSR-2 × GAB-6’ as the top three stable crosses for fruit yield per plant. Overall, ‘ISD-006 × GRB-5’ appeared to be an outstanding cross for fruit yield and its attributing traits in terms of heterobeltiosis and standard heterosis in individual and pooled environments. As well as it was found to be average stable for four major traits and stable in favourable environments for fruit weight and yield per plant. Also, incorporating hybrids identified in this experiment might potentially result in transgressive segregants in brinjal.

Haplotype-resolved T2T genome assemblies and pangenome graph of pear reveal diverse patterns of allele-specific expression and the genomic basis of fruit quality traits

Hybrid crops often exhibit increased yield and greater resilience, yet the genomic mechanism(s) underlying hybrid vigor or heterosis remain unclear, hindering our ability to predict the expression of phenotypic traits in hybrid breeding. Here, we generated haplotype-resolved T2T genome assemblies of two pear hybrid varieties, ‘Yuluxiang’ (YLX) and ‘Hongxiangsu’ (HXS), which share the same maternal parent but differ in their paternal parents. We then used these assemblies to explore the genome-scale landscape of allele-specific expression (ASE) and create a pangenome graph for pear. ASE was observed for close to 6000 genes in both hybrid cultivars. A subset of ASE genes related to aspects of fruit quality such as sugars, organic acids, and cuticular wax were identified, suggesting their important contributions to heterosis. Specifically, Ma1, a gene regulating fruit acidity, is absent in the paternal haplotypes of HXS and YLX. A pangenome graph was built based on our assemblies and seven published pear genomes. Resequencing data for 139 cultivated pear genotypes (including 97 genotypes sequenced here) were subsequently aligned to the pangenome graph, revealing numerous structural variant hotspots and selective sweeps during pear diversification. As predicted, the Ma1 allele was found to be absent in varieties with low organic acid content, and this association was functionally validated by Ma1 overexpression in pear fruit and calli. Overall, these results reveal the contributions of ASE to fruit-quality heterosis and provide a robust pangenome reference for high-resolution allele discovery and association mapping.

Challenges in bermudagrass production in the southeastern USA

AbstractBermudagrass (Cynodon dactylon (L.) Pers.) is one of the primary perennial forages in the southeastern USA. Newer hybrid cultivars have superior production and nutritive value compared to common ecotypes. However, there are many challenges facing bermudagrass production in the region. First, the bermudagrass stem maggot (BSM; Atherigona reversura Villeneuve) has severely damaged bermudagrass throughout the region. Strategically timed pyrethroid applications significantly reduce adult BSM populations, but efforts are needed to develop integrated pest management plans. Second, an increasing number of producers are noting challenges with green‐up following winter dormancy. This may be attributed to disease, unbalanced soil fertility, and weed pressure. Perhaps one of the most limiting factors for continued production is the deficit of sprigs and trained personnel to sprig hybrid bermudagrasses. This research is critically important as the need for cold‐tolerant bermudagrass is increasing as tall fescue (Lolium arundinaceum (Schreb.) S. J. Darbyshire) is declining due to changes in temperature and precipitation throughout the northern parts of the region. Plant breeders are investigating hybrid bermudagrass at latitudes >35° with respect to freeze or cold tolerance. Despite the many challenges facing hybrid bermudagrass in the southeastern USA, researchers are working to ensure its persistence, productivity, and availability for the future.

Morphological Characterization of Some Capia Pepper (Capsicum annuum L.) Genotypes

Capsicum annuum (Capia), a member of the Solanaceae family, has a rich genetic diversity in fruit and plant traits. To select Capia pepper genotypes with desirable morphological traits for the development of new hybrid capia pepper varieties, this study aimed to characterize genetic accessions generated from local populations, and standard and hybrid cultivars using morphological characters. One hundred and twelve genotypes were identified using 15 morphological traits (11 qualitative and 4 quantitative) and quantitative traits were measured while qualitative traits were observed. Cluster and Principal Component Analysis (PCA) was applied to determine the relationship between the lines identified as a result of single plant selection. As a result of the cluster analysis, a dendrogram was prepared to evaluate the morphological similarity between the lines, and nineteen groups were identified based on 15 variables. In Principal Component Analysis, six PC axes explained 66.2% of the total variation. As a result of the study, high morphological variability was observed among pepper lines. This evaluation of plant trait variability can assist geneticists and breeders in identifying populations with desirable characteristics for inclusion in pepper breeding programs.

Mapping the CP-Transgene Insert in the Papaya Genome and Developing a Hermaphrodite Transgenic Hybrid with Broad-Spectrum Resistance to Papaya Ringspot Virus.

Papaya ringspot virus (PRSV) limits papaya production worldwide. Previously, we generated transgenic lines of hybrid Tainung No.2 (TN-2) carrying the coat protein (CP) gene of PRSV with broad resistance to PRSV strains. Unfortunately, all of them were female, unacceptable for growers and consumers in practical applications. With our reported flanking sequences and the newly released papaya genomic information, the CP-transgene insert was identified at a non-coding region in chromosome 3 of the papaya genome, and the flanking sequences were verified and extended. The female transgenic line 16-0-1 was first used for backcrossing with the parental Sunrise cultivar six times and then followed by selfing three times. With multi-level molecular markers developed from the PRSV CP transgene and the genomic flanking sequences, the presence and zygosity of the CP transgene were characterized at the seedling stage. Meanwhile, hermaphrodite genotype was identified by a sex-linked marker. With homozygotic transgene and horticultural properties of Sunrise, a selected hermaphrodite individual was propagated by tissue culture (TC) and used as maternal progenitor to cross with non-transgenic parental cultivar Thailand to generate a new hybrid cultivar TN-2 with a hemizygotic CP-transgene. Three selected hermaphrodite individuals of transgenic TN were micropropagated by TC, and they showed broad-spectrum resistance to different PRSV strains from Taiwan, Hawaii, Thailand, and Mexico under greenhouse conditions. The selected clone TN-2 #1, with excellent horticultural traits, also showed complete resistance to PRSV under field conditions. These selected TC clones of hermaphrodite transgenic TN-2 provide a novel cultivation system in Taiwan and elsewhere.

Potential of increasing yield of spring Brassica napus canola by using Brassica rapa gene pool with emphasis on yellow sarson

Context Broadening the genetic base of canola (Brassica napus) is needed to develop improved hybrid cultivars. Wide genetic diversity is present in its parental species B. rapa and B. oleracea. In the case of B. rapa, the yellow sarson type from Asia is genetically distinct from all other types. Aims The objective of this research was to investigate the prospect of using yellow sarson to improve the performance of hybrid canola cultivars. Methods Inbred B. napus canola lines derived from an B. napus × B. rapa interspecific cross, and their F1 hybrids with the B. napus parent, as a tester, were compared on agronomic and seed quality traits; the inbreds were also evaluated for genetic diversity by using molecular markers. Key results Seed yield of the hybrids was significantly greater than the inbreds and the B. napus parent and exhibited more than 15% mid-parent heterosis (MPH). Genetic diversity did not show significant correlation with seed yield in the inbred population; however, it showed a positive correlation with MPH. Inbred yield as well as MPH showed a positive correlation with hybrid yield. For other traits, the performance of the inbreds showed a significant positive correlation with the performance of the hybrids; the average MPH for these traits was low or close to zero. Conclusions The yellow sarson gene pool showed great potential for use in the breeding of hybrid canola. Implications The knowledge gained and germplasm developed from this research can be used by breeders and researchers to develop improved canola cultivars.

Trellising is advantageous over ground culture for out-of-season, protected production and storage of sweet acorn squash

Acorn squash (Cucurbita pepo) have been a familiar item at produce stands for decades in the United States and Canada, but little known or appreciated elsewhere. Following the breeding and development of sweet-fleshed acorn squash in Israel and its commercial introduction in 2007, acorn squash became a high-priced, popular produce item there. Scarcity of supply in winter has led to attempts to fill the consumer demand by using available protected cultivation infrastructure in the relatively mild area of southwestern Israel for production. Such production has proven feasible but it was not determined whether it would be preferable to allow the plants to simply grow sprawling on the ground or vertically, using trellises to train the plants to grow erect. Two sweet acorn squash hybrid cultivars differing in fruit size were compared, growing on the ground or on trellises, for yield, quality, and storability of the fruits. The hybrids bore fully ripe fruits from December through February, producing 56% higher yields when trellised rather than when allowed to grow on the ground. The fruits of trellised plants of both hybrids were more uniformly black-green and firmer than those of ground-grown plants. Their dry matter content at harvest and after 78 days of storage was very high, averaging 28% and 25%, respectively. Total soluble solids content of the fruit flesh from trellised plants was 19% at harvest and an extraordinary 20% after storage at 10°C, 70% RH. The fruit flesh of trellised plants was also more highly colored and had higher carotenoid, ascorbate, and anti-oxidant contents. Overall, trellising of sweet acorn squash during the winter under protected cultivation resulted in significantly higher yields and the finest fruit quality.

Morphological characterization and molecular marker-assisted selection for resistance to Tobacco mosaic virus (TMV) and Tomato spotted wilt virus (TSWV) in S2 population of capia pepper (Capsicum annuum L.)

Morphological characterization and molecular marker-assisted selection for resistance to Tobacco mosaic virus (TMV) and Tomato spotted wilt virus (TSWV) in S2 population of capia pepper (Capsicum annuum L.)

Effects of harvest height and time on hay yield and quality of some sweet sorghum and sorghum Sudangrass hybrid varieties.

This experiment was conducted in the Research and Application Field of Canakkale Onsekiz Mart University, Faculty of Agriculture, during the 2020 and 2021 summer period. The objective of this experiment was to determine the effects of different harvesting heights on forage yields and crude ash, fat, protein, and carbon and nitrogen content of leaves and stalks of sweet sorghum (SS) and sorghum sudangrass hybrid (SSH) cultivars. Nutri Honey and Nutrima varieties of SSH and the M81-E and Topper-76 varieties of SS were used in this study. The experiment was conducted using the randomized complete block design with four replications. The main plots each included two early and late varieties of SS and SSH cultivars, while the subplots were used to test different harvesting heights (30, 60, 90, 120, 150 cm) and physiological parameters of each crop. The results of this study showed that dry forage yields increased with plant growth, with the amount of forage produced at the end of the growth cycle increasing 172.2% compared to the early growth stages. Carbon (C) content of leaves decreased by 6.5%, nitrogen (N) by 46%, crude protein (CP) by 54%, crude fat (CF) by 34%, while crude ash (CA) content increased by 6% due to the increase in plant height harvest. At the same time, in parallel with the increase in plant height at harvest, the nitrogen content of the stems of the plants decreased by 87%, crude protein by 65%, crude ash by 33% and crude fat by 41%, while the carbon content increased by 4%. As plant height at harvest increased, hay yield increased but nutrient contents of the hay decreased. However, the Nutrima, Nutri Honey and M81-E sorghum cultivars, harvested three times at heights of 90 to 120 cm, are recommended for the highest yield.

Features of the water regime and photosynthesis in hybrid forms of cherry plum under the dry wind season conditions

Background. The results of a study on the drought resistance of cherry plum hybrid forms are presented. Water retention capacity of leaves and chlorophyll fluorescence were measured under the simulated conditions close to the dry wind season.Materials and methods. The water regime parameters were studied for five cherry plum genotypes in 2021 and 2022. Leaves of four hybrid forms developed at the Nikita Botanical Gardens and the reference cherry plum hybrid cultivar ‘Rumyanaya Zorka’ (Prunus rossica Erem.) were taken into the experiments. Using the guidelines by G. N. Eremeev and A. I. Lishchuk, a series of experiments on controlled leaf wilt at the air temperature of +27°C and relative humidity of 30% were conducted on cherry plum to assess the functional state of the photosynthetic apparatus during the development of water stress under dry wind conditions. The experiments were carried out in a Binder climate chamber. Chlorophyll fluorescence was measured using a portable Floratest fluorometer. The measurements were based on the parameters of the chlorophyll fluorescence induction curve (CFI) obtained on native leaves. The leaves of cv. ‘Rumyanaya Zorka’ in the state of complete watering served as the reference.Results and discussion. Dependence was identified between chlorophyll fluorescence and moisture content in the leaves of the studied samples. The hybrids were found to respond to drought in different ways. A relatively increased ability to retain moisture during dehydration was observed in form 12/26 whose leaves gave off moisture more slowly and restored their turgor better. It is promising for cultivation in areas with insufficient water supply. Form 99/36 had the lowest potential drought resistance. Forms 99/14 and 9/28 occupied an intermediate position.

Directional Breeding Generates Distinct Genetic Diversity in Hybrid Turf Bermudagrass as Probed with Simple Sequence Repeat Markers

Bermudagrass (Cynodon spp.) is a drought-resistant warm-season turfgrass adapted to the southern and transitional zones in the United States. Multiple hybrid cultivars have been developed and released for use as turfgrass, and others are still undergoing development. Increasing genetic diversity of commercial cultivars is vital to stress tolerance. A DNA profiling study of 21 experimental selections from the Oklahoma State University turfgrass breeding program and 11 cultivars was conducted using 51 simple sequence repeat primer pairs across the bermudagrass genome. A pairwise genetic relationship analysis of the genotypes using 352 polymorphic bands showed genetic similarity coefficients ranging from 0.59 to 0.89. The average pairwise population differentiation values were 0.012 for the 11 cultivars and 0.169 for the 21 selections. A cluster analysis using the unweighted paired group with the arithmetic average method grouped the entries into six clusters. A correlation analysis identified different levels of pairwise genetic relationships among the entries that largely reflected parental relationship. Directional breeding and selection for cold hardiness or drought resistance created progeny that had distinct genetic diversity in the tested bermudagrasses. It is evident that an increase in genetic diversity of the existing cultivar pool with the release of one or more experimental selections for commercial use will strengthen and improve bermudagrass systems.

Application of machine learning for identification of heterotic groups in sunflower through combined approach of phenotyping, genotyping and protein profiling

Application of machine learning in plant breeding is a recent concept, that has to be optimized for precise utilization in the breeding program of high yielding crop plants. Identification and efficient utilization of heterotic grouping pattern aided with machine learning approaches is of utmost importance in hybrid cultivar breeding as it can save time and resources required to breed a new plant hybrid/variety. In the present study, 109 genotypes of sunflower were investigated at morphological, biochemical (SDS-PAGE) and molecular levels (through micro-satellites (SSR) markers) for heterotic grouping. All the three datasets were combined, scaled, and subjected to unsupervised machine learning algorithms, i.e., Hierarchical clustering, K-means clustering and hybrid clustering algorithm (hierarchical + K-means) for assessment of efficiency and resolution power of these algorithms in practical plant breeding for heterotic grouping identification. Following the application of machine learning unsupervised clustering approach, two major groups were identified in the studied sunflower germplasm, and further classification revealed six smaller classes in each major group through hierarchical and hybrid clustering approach. Due to high resolution, obtained in hierarchical clustering, classification achieved through this algorithm was further used for selection of potential parents. One genotype from each smaller group was selected based on the maximum seed yield potential and hybridized in a line × tester mating design producing 36 F1 cross combinations. These F1s along with their parents were studied in open field conditions for validating the efficacy of identified heterotic groups in sunflowers genetic material under study. Data for 11 agronomic and qualitative traits were recorded. These 36 F1 combinations were tested for their combining ability (General/Specific), heterosis, genotypic and phenotypic correlation and path analysis. Results suggested that F1 hybrids performed better for all the traits under investigation than their respective parents. Findings of the study validated the use of machine learning approaches in practical plant breeding; however, more accurate and robust clustering algorithms need to be developed to handle the data noisiness of open field experiments.

Tannin and Iron-Reactive Phenolics Content in Red Cold-Hardy Hybrid Grape Tissues throughout Development and Ripening.

Phenolic compounds, especially tannins, are important for red wine quality. Wines made from cold-hardy hybrid grape cultivars have much lower tannin concentrations than wines from Vitis vinifera grape cultivars. This study assessed the phenolics content of berry tissues of three red cold-hardy hybrid cultivars in comparison to V. vinifera cv. 'Pinot noir' throughout development and ripening. Basic chemical properties, iron-reactive phenolics content, and tannin content were evaluated in the juice, skins, and seeds of Vitis spp. cvs. 'Crimson Pearl', 'Marquette', and 'Petite Pearl' and 'Pinot noir' at six time points from one week post-fruit set to harvest in 2021 and 2022. 'Crimson Pearl' displayed similar iron-reactive phenolics and tannin contents in juice, skins (22.6-25.4 mg/g dry skin and 8.0-12.2 mg/g dry skin, respectively), and seeds (12.8-29.8 mg/g dry seed and 4.2-22.0 mg/g dry seed, respectively) as 'Petite Pearl' and 'Marquette' at harvest in 2022. The hybrid cultivars showed a similar trend of phenolic accumulation as 'Pinot noir' but resulted in overall lower content in skins and seeds. Despite differences in developmental trends, the three hybrid grape cultivars displayed similar phenolic content at harvest ripeness. This is the first study examining the phenolic content of 'Crimson Pearl' and 'Petite Pearl' throughout berry development and ripening. This study provides important information for the wine industry to make informed decisions on making wine with these cultivars.

Effect of different salinity on seed germination, growth parameters and biochemical contents of pumpkin (Cucurbita pepo L.) seeds cultivars

Soil and water salinity is an important limiting factor affecting yield and production levels in arid and semi-arid areas. Salt tolerance during germination is an important parameter that also affects the other plant development stages. In this respect, this study was designed to determine the responses of pumpkin seed varieties (Develi, Ürgüp, Hybrid) to different NaCl salinities. The study was carried out in 2022 in the laboratory of Biosystems Engineering Department of Erciyes University in randomized plots design with 3 replications. Experiments were conducted with 5 different water salinity. Germination percentage (GP), germination index (GI), mean germination time (MGT), seedling vigor index (SVI), ion leakage (Il), radicula length (RL) and plumule length (PL), root and shoot fresh and dry weights and some mineral composition (Na, K, Ca) were examined. Proline, antioxidant capacity, total phenolic and DPPH content were significantly affected by salinity. In scatter plot correlation analysis SVI a positive correlation was observed between GP (r2 = 0.774), GI (r2 = 0.745), RL (r2 = 0.929), FRW (r2 = 0.837), FSW (r2 = 0.836), DRW (r2 = 0.894), AC (r2 = 0.747), TP (r2 = 0.640) and DPPH (r2 = 0.635). It was determined that there were negative correlations between SVI and MGT (r2 = − 0.902), II (r2 = − 0.588), DSW (r2 = − 0.682) and PR (r2 = − 0.344). Present findings revealed that investigated parameters were significantly affected by increasing salinity levels. While Hybrid cultivar was the most affected by salinity, Develi cultivar was found to be resistant to saline conditions.

Genetic variability and QTL mapping of morphological traits and inflorescence prolificacy in African bermudagrass

AbstractAfrican bermudagrass (Cynodon transvaalensis Burtt‐Davy) (2n = 2x = 18) has unique morphological characteristics such as finer leaf blades and shorter internodes that are important to improving turf qualities (i.e., texture and density) as compared to other Cynodon species. It has been extensively used to cross with common bermudagrass (Cynodon dactylon Pers. var. dactylon) in developing high‐quality interspecific [C. dactylon (L.) Pers. × C. transvaalensis Burtt‐Davy] F1 hybrid cultivars for turf use. However, the molecular basis of its morphological variation is unknown. Accordingly, the objectives of this study were to estimate the heritability and identify quantitative trait loci (QTL) associated with morphological and reproductive traits. A first‐generation self‐pollinated (S1) population of 109 individuals was evaluated for plant height (PH), leaf blade width (LBW) and leaf blade length, stem internode diameter and length, and inflorescence prolificacy (IP) in a replicated field trial over three seasons (2018–2020). The broad‐sense heritability estimates ranged from 0.31 (PH) to 0.80 (IP). Twenty‐four QTL were identified and nine of them were consistent ones. Fifteen candidate genes were found at a major and consistent QTL region associated with LBW. Frequent QTL colocations were found among morphological traits and between morphological traits and IP, partially explaining the significant correlation. The findings provide critical information and resources toward understanding the genetic basis associated with morphological and reproductive traits within C. transvaalensis and could contribute to marker‐assisted selection for breeding new turf‐type bermudagrass cultivars.

Participatory breeding in organic systems: Experiences from maize case studies in the United States

Participatory breeding and crop selection can satis­fy the needs of underserved groups of farmers (e.g., organic producers, farmers producing spe­cialty grain for niche markets) neglected by the modern global seed industry. Participatory research methods that value local knowledge and facilitate the active involvement of producers, researchers, and other actors involved in the agri-food system are tactics that can help us achieve sustainable agri­culture. Interest in the use of participatory methods to increase the value of U.S. land-grant universities to society has grown rapidly during the last decade. Interest includes re-engagement in the develop­ment of maize hybrids that perform well in a diverse range of heterogeneous growing environ­ments and that are better suited for sustainability-minded producers, buyers, and consumers. Sys­tems-based breeding aimed at protecting the envi­ronment and providing food, fiber, and energy while considering equity issues, has been proposed as a way to overcome the shortcomings of privat­ized approaches. In this article, we consider recent projects that use collaborative methods for hybrid maize breeding, cultivar testing, and genetic research to develop, identify, and deliver traits associated with crop performance, quality, and sus­tainability. Three case studies consider the efforts focused on developing non-GMO varieties for organic and specialty markets. We find that, unlike many successful efforts focused on the improve­ment of other crops, there are few promising mod­els for participatory breeding of hybrid maize. Even though many projects have sought to involve stakeholders with a variety of methods, all have struggled to meaningfully engage farmers in maize hybrid improvement. Still, our reflection of case studies calls for systems-based breeding and sug­gests a path forward. This route would seek to address the needs, perspectives, and values of a broader range of actors participating in the food system by leveraging technologies and infrastruc­ture in service of the public. Land-grant universities are well positioned to play a crucial role in coordi­nating efforts, facilitating partnerships, and sup­porting breeding programs that satisfy societal wants that include health, equity, and care.