Promising Lines Research Articles

Transfer of Stress Resilient QTLs and Panicle Traits into the Rice Variety, Reeta through Classical and Marker-Assisted Breeding Approaches.

Reeta is a popular late-maturing high-yielding rice variety recommended for cultivation in the eastern Indian states. The cultivar is highly sensitive to submergence stress. Phosphorus deficiency is an additional constraint for realizing high yield. The quantitative trait loci (QTLs), Sub1, for submergence and Pup1 for low phosphorus stress tolerance along with narrow-grained trait, GW5 were introgressed into the variety from the donor parent, Swarna-Sub1 through marker-assisted breeding. In addition, phenotypic selections for higher panicle weight, grain number, and spikelet fertility were performed in each segregating generation. Foreground selection detected the 3 target QTLs in 9, 8 and 7 progenies in the BC1F1, BC2F1, and BC3F1 generation, respectively. Recurrent parent's genome recovery was analyzed using 168 SSR polymorphic markers. The foreground analysis in 452 BC3F2 progenies showed five pyramided lines in homozygous condition for the target QTLs. No donor fragment drag was noticed in the Sub1 and GW5 QTLs carrier while a segmentwas observed in the Pup1 carrier chromosome. The developed lines were higher yielding, had submergence, and had low phosphorus stress-tolerance alongwith similar to the recipient parent in the studied morpho-quality traits. A promising pyramided line is released in the name of Reeta-Panidhan (CR Dhan 413) for the flood-prone areas of Odisha state.

Genetic Parameters and Diversity Studies Among Morphological Traits in Breeding Lines of Garlic (Allium Sativum L.)

Thirty-four promising lines of garlic were grown in randomized block design with three replications under the latesown season in 2019-20 at Vegetable Research Farm of C. S. Azad University of Agriculture and Technology, Kalyanpur, Kanpur. The mean sum of squares showed highly significant differences among the lines for all the traits studied, indicating the presence of a sufficient amount of genetic variability. The moderate to higher magnitude of the coefficient of variation at genotypic as well as phenotypic levels was noticed for number of cloves per bulb, marketable bulb yield, average weight of bulb, average weight of cloves and plant height. High heritability coupled with high genetic advance as percent of mean was observed for plant height, leaf length, leaf width, polar diameter, number of cloves per bulb, average weight of bulb and average weight of cloves. Marketable bulb yield was positively and significantly correlated with the total bulb yield and dry matter content whereas, a significant negative correlation with leaf width. All the thirtyfour lines of garlic were grouped into five clusters based on Mahalanobis D2 statistics using Tocher’s method. The cluster II and V had among the moderate genetic distance having higher total bulb yield performance along with its contributing traits. The genotypes from cluster IV and V had the most divergent clusters and were suitable for high yielding garlic genotypes among the various advanced breeding lines under late sown conditions. Bangladesh J. Bot. 52(2): 225-233, 2023 (June)

O-010 The ULTRA trial: transvaginal ULTRAsound-guided ovarian ablation using the novel May Health device in women with PCOS-related infertility: first–in-human feasibility clinical trial

Abstract Study question Is transvaginal ULTRAsound (TVUS)-guided ovarian ablation using May Health device feasible, safe, and effective in inducing ovulation in Clomiphene citrate and/or Letrozole (CC/LTZ)-resistant PCOS women? Summary answer TVUS-guided ovarian ablation using the May Health device seems feasible, safe and effective in inducing ovulation in PCOS-related anovulatory infertility, with additional, larger studies needed. What is known already Laparoscopic ovarian drilling (LOD) is widely accepted and recommended as an effective second line treatment in PCOS-related infertility. However, it is an invasive procedure that requires general anaesthesia and carries significant risks. Furthermore, the off-the-shelf devices used for LOD are not specifically designed to precisely deliver the desired and effective amount of ablation. In contrast, the May Health device has been designed to induce a precisely calculated amount of ovarian ablation via a much less invasive route without general anaesthesia. May Health therefore transforms an invasive surgical procedure to an office-based technique similar in access to the well-established oocyte retrieval. Study design, size, duration This study included two phase-1 feasibility, single-arm clinical trials running in parallel in the US and EU assessing the May Health Device in performing TVUS-guided ovarian ablation in anovulatory PCOS women resistant to first-line ovulation induction drugs. Sample size was 35 participants with post-procedure follow-up (FU) of 24 months in EU and 12 months in US. Endpoints included procedure feasibility (successful ablation of at least one ovary), safety, and effectiveness (ovulation and pregnancy rates). Participants/materials, setting, methods Seven fertility centres (UK, France, Belgium, US) participated in the trials. Participants were CC/LTZ-resistant PCOS women aged 18-40 years. PCOS was diagnosed according to Rotterdam criteria. Participants underwent TVUS-guided ovarian ablation using May Health device. The initial five participants underwent laparoscopy concurrent with TVUS-ablation. Post-procedure, serum progesterone was measured weekly until confirmation of ovulation or up to 12 weeks. Women were evaluated at 3 and 6 months, then telephoned at 9, 12 and 24 months. Main results and the role of chance Twenty-three participants (mean±sd age, 31.8±3.1years; BMI, 29.8±5.0kg/m2) underwent May Health TVUS-guided ovarian ablation and completed at least three-months FU. Of those, 10 (43.5%) ovulated spontaneously during the first three months. Six more women ovulated between three- and nine-months FU, some with CC/LTZ, giving a total ovulation rate of 69.6% (16/23). Of the 11 participants who completed nine-months FU, five conceived. Two more participants conceived before 9-months giving a total pregnancy rate of 53.8% (7/13). In 19 cases (82.6%), ablation was achieved successfully in both ovaries, while in four cases (17.4%) one of the ovaries was not ablated either because it was too small (as per protocol) (n = 3) or inaccessible (n = 1). Overall, 14 participants experienced 29 adverse events (AEs), of which 25 were mild, two moderate and two severe. Nine mild/moderate AEs were deemed related to the device/ablation procedure. Examples of mild/moderate AEs included mild self-limiting vaginal bleeding (n = 5), pain (n = 5) and headache (n = 2). None of the severe AEs were deemed related to the device/ablation procedure. One participant in phase1a who underwent laparoscopy concurrent with the ablation, sustained a bowel injury involving the ilium near the ileocecal junction. Independent expert investigation concluded that the injury was likely caused by laparoscopic veress needle. Limitations, reasons for caution One possible limitation of this study is the lack of a comparator treatment / placebo arm. However, this was not necessary for this feasibility phase 1 trial. Furthermore, given the nature of TVUS-ovarian ablation, it would be difficult to compare it with other ovulation induction drugs or to a placebo. Wider implications of the findings These preliminary data suggest that the novel May Health device offers a promising office-based second line ovulation inducing procedure for CC/Letrozole-resistant anovulatory PCOS women. Trial registration number NCT03760926

FH-444: A HIGH YIELDING AND SUPERIOR FIBER QUALITY UPLAND COTTON VARIETY SUITABLE FOR COTTON GROWING AREAS OF PUNJAB, PAKISTAN

FH-444 is a new Bt cotton variety which was released during the year 2020-21 by Cotton Research Station, Ayub Agricultural Research Institute, for irrigated areas of Punjab, Pakistan to maintain fiber quality and production through gradually replacement of existing cotton cultivars to avoid the yield losses caused by insect, pest and unexpected disease attacks. The FH-444 possesses drought tolerance and very good combination of traits to meet the requirements of the farmers, pickers, ginners, spinners and textile industry. The evaluation of this promising line was started during 2011-12 in different yield tests viz: preliminary & advance yield trials, Provincial Coordinated Cotton Trial (PCCT), National Coordinated Varietal Trial (NCVT), Distinctness, Uniformity and Stability (DUS) Trial, Agronomic trials, 1.25 Acre trials etc. In preliminary yield trials, FH-444 showed 45.96% increase in yield (3592 kg/ha) over standard variety FH-113 (2461 kg/ha) during 2011-12 while in advanced yield trials, FH-444 exhibited 23.61% increase in yield (3408 kg/ha) over standard variety FH-113 (2757 kg/ha) during 2013-14. It was also found that the effects of Cotton Leaf Curl Disease (CLCuD) were low (1.7 %) in FH-444 during growing season of 2014-15, while FH-142 showed increased incidence of attack (4.9%). FH444 demonstrated significant resistance with respect to thrips, whitefly, jassid and pink bollworm infestation. In present study it was found that the variety FH-444 possesses higher yield potential and will contribute to improve cotton yield and production under different stress conditions.

AGRONOMIC CHARACTERIZATION OF AN EMS-MUTAGENIZED POPULATION FOR SELECTING HIGH-YIELDING AND GLUTENENRICHED INDUSTRIAL WHEAT

A mutant population was generated using a popular wheat cultivar of Bangladesh; BARI GOM-28, with ethyl methanesulfonate (EMS) to create diversity in terms of different agronomic characteristics and grain quality parameters. An EMS concentration ranging from 0.2% to 1.2% was used and the optimum was found to be 0.8%. This study was initiated with 16,000 seeds, where 1,581 lines survived under greenhouse conditions up to M4 generation. Through 3 subsequent field trials, 3 promising lines, namely, 0037/17, 0020/17 and 0023/17 were selected with enhanced spike length, number of spikes per plant, number of spikelets per spike, number of grains per spike, grains weight per plant and 1000-grain weight. Such improved agronomic traits contributed towards a greater yield potential of 0037/17 (5.94-6.10 t ha-1), 0020/17 (5.47-5.54 t ha-1) and 0023/17 (4.97-5.20 t ha-1) than BARI GOM-28 (3.63-3.69 t ha-1) in the multi-location trial. Improvement in certain bread-making qualities like wet gluten content (>28%) and total protein content (~13%) was also observed and compared to BARI GOM-28 which had 22% wet gluten and 11% total protein. Therefore, these mutant lines could be used as a valuable resource for genetic studies to dissect the function of the genes controlling such desired parameters as well as superior breeding lines.

МОЛОЧНАЯ ПРОДУКТИВНОСТЬ КОРОВ, ПРОИСХОДЯЩИХ ИЗ ПЕРСПЕКТИВНЫХ ВЕТВЕЙ ГОЛШТИНСКОЙ ПОРОДЫ

The aim of the study was to study the milk productivity of cows originating from different promising branches and lines of the Holstein breed. The population studied was Wis Back Idial 101341, Reflection Sovering 198998, Montvik Chieftain 95679, Siling Traijun Rokita 252803 and Roseife City 267150. The best indicators were established in cows of the line V.B. Ideal for the 1st and 3rd lactation (7086 and 7431 kg of milk with the amount of milk fat 271 and 285 kg and the amount of milk protein 225 and 238 kg), and the difference is statistically significant (P<0.05-0.001) in relation to other lines. In second place are the animals of the Reflection Sovering line. Cows of the line S.T. Rokita had a high milk fat content (3.85 and 3.94%) at P<0.05. In V. Aidial's line, the best milk yield indicators are shown by first-calf heifers of the SWEET-HAVEN TRADITION branch (7143 kg). In the R. Sovering line, cows of the TO-MAR BLACKSTAR-ET branch showed the greatest increase in milk yield by 89-1226 kg, milk fat yield by 4-42 kg, milk protein yield by 2-37 kg (P<0.001), and high milk fat content (3.86%) of the cow of the S-W-D VALIANT line (P<0.01-0.001). According to the 3rd lactation in the line of R. Sovering, cows of the S-W-D VALIANT branch show an advantage in milk yield by 353-831 kg of milk, mass fraction of fat - by 0.05-0.08%, milk fat yield - by 20-36 kg and milk protein yield - by 12-26 kg (P<0.05-0.01). As a result of the study, it was found that the use of animal branches of SWEET-HAVEN TRADITION, ROCKALLI SON OF BOVA, TO-MAR BLACKSTAR-ET and WALKWAY CHIEF MARK makes it possible to obtain high milk productivity from them.

Genetic Variability of Coffee (Coffea arabica L.) Germplasm in Biennial Bearing and Its Influence on Selection Efficiency

Arabica coffee is a perennial cash crop and highly affected by biennial bearing which disturbs farmers’ annual income and world’s coffee industries. Developing nonbiennial bearing variety is prominent in addition to applying field management practices. This study was conducted from 2012 to 2020 in southwestern Ethiopia at Tepi and Gera to test the extent of genetic variability among Arabic coffee germplasm in biennial bearing and understand the influences of bienniality on advanced selection. The pooled analysis of variance revealed handiness of genetic variability in yield and biennial bearing. The moderate genotypic coefficient of variation (10–20%), heritability (30–50%), and high genetic advance as percentage of the mean (>20%) were manifested in yield and biennial bearing. Response to selection and selection efficiency were negatively affected by biennial bearing. Early selection excluded 30–40% of the top high yielders from advanced selection. Selection at four harvesting seasons revealed 90% and more selection efficiency. Thus, one has to be conscious of the alternate bearing nature of lines during advanced selection. Both T43/11 and T51/11 were among the top high yielders and showed low biennial bearing at Gera and Tepi. T33/11, T49/11, T55/11, and T61/11 showed very low biennial bearing at both locations. These are promising lines and could be recommended for further biennial bearing improvement breeding programs.

Agromorphological and Physiological Performance of Ethiopian Common Bean (Phaseolus vulgaris L.) Genotypes under Different Agroecological Conditions.

The objectives of this study were to assess the agronomic performance of common bean genotypes, previously selected for their response to infestation, by Mexican bean weevil and to identify promising lines that can be used as parents in a downstream breeding program. Field experiments were conducted using 144 genotypes under three different agro-ecologies in an unbalanced incomplete block design with three replications. Data on 15 agro-morphological traits were collected, and multivariate methods were used to examine the patterns of variation among the genotypes. The genotypes revealed a high level of phenotypic diversity for all agronomic traits. Six principal components, which contributed 84% of the total variation among the genotypes, were identified. The 15 agro-morphological traits classified the genotypes into three distinct major clusters and sub-clusters. The clustering patterns of the genotypes were according to the seed size, whereby the small and medium beans were distinctly separated from the large-seeded beans. The study established the existence of considerable genetic variations among common bean genotypes. Unique genotypes, such as Nasir, Awash Melka, and RAZ-36 from Cluster I, RAZ-2, RAZ-11, and RAZ-42 from Cluster II, and SER-125, SCR-15, MAZ-200, MAZ-203, and RAZ-120 from Cluster III, were selected based on their distinct agronomic performance. The selected genotypes could be useful for the common bean breeding program.

Evaluation of Introgressed Lines of Sunflower (Helianthus annuus L.) under Contrasting Water Treatments

Drought stress is a major production constraint in crops globally. Crop wild relatives are important sources of resistance and tolerance for both biotic and abiotic stresses, respectively. A breeding program was initiated to introgress drought tolerance in sunflowers through hybridization between the wild species Helianthus argophyllus and the cultivated pool of H. annuus. Selection was carried out from the F2 to F5 segregating populations for the silver canopy, high cuticular wax, small leaf area, single heading and high oil content. Cuticular wax ranged between 8.72 µg g−1 and 17.19 µg g−1 in the F5 offspring. The selected F5 breeding lines were self-pollinated to obtain the F6 generation. Thereafter, this F6 was compared with the non-adapted elite sunflower germplasm in a factorial complete randomized design with different water treatments; i.e., comparing fully irrigated (100%, T0) versus 75% (T1), 50% (T2) and 25% (T3) of total irrigation. The comparison between the two types of the germplasm showed that drought-tolerant breeding lines had a comparatively lesser decrease in leaf area (0, 11, 22%) and shoot length (4, 21, 28%) than the elite germplasm, which experienced a decrease in leaf area (21%, 33% and 40%) and shoot length (17, 27 and 34%) under the various drought treatments. Moreover, drought-tolerant breeding lines had 100% more root shoot ratios than the elite germplasm (20%) in T3 when compared with control. Several drought-tolerant promising lines (D-2, D-5 and D-27) were selected due to their high leaf area, great root length and increased root to shoot ratio under T3. Some of the lines could be directly used for the development of drought-tolerant hybrids. Combining ability testing indicated that D-27 (F7) was a good general combiner for seed yield plant−1 and oil content after mating with male-line RSIN.82. Resulting hybrids could help to minimize seed yield loss due to water stress and to achieve profitable cultivation of sunflowers in arid regions of Pakistan.

Using Chromosomal Abnormalities and Germination Traits for the Assessment of Tritipyrum Amphiploid Lines under Seed-Aging and Germination Priming Treatments

Primary Trans Chromosomal Tritipyrum (PTCT) amphiploid is a new cereal grown in saline soil and brackish water for grain and forage production. We evaluated the tolerance to seed deterioration in 13 promising PTCT lines, assessing accelerated aging (AA) tests by using AA boxes with 100% relative humidity at 40 °C for 72 h. The (Ma/b)(Cr/b)F4 and (St/b)(Cr/b)F4) PTCT lines, more sensitive to seed aging, were primed with NaCl, Salicylic Acid (SA), and Polyethylene Glycol (PEG) to increase the seed vigor of artificially aged seeds. Germination and emergence traits, biochemical parameters, and chromosomal abnormalities induced by artificial aging were measured in deteriorated and not-deteriorated seeds. The highest reduction percentages related to seed vigor were observed in (Ka/b)(Cr/b)F2 (34.52) and La(4B,4D)/b (28.15) lines, while the lowest was found in (Ma/b)(Cr/b)F4 (7.65) and (St/b)(Cr/b)F4 (7.46) lines. Seed aging also increases electrolytes, potassium, and protein leakages. Chromosomal abnormalities are caused by seed aging that interferes with chromosome behaviors during cell division. Seed priming on aged seeds revealed an increase in the germination percentage (GP) with PEG treatment, while the priming by SA showed an increase in seedling traits, such as the seedling length (SL2). In conclusion, we highlighted the potential use of different PTCT lines and the effective use of seed priming on deteriorated seed to enhance seed viability and seedling vigor as a useful tool for sustainable agriculture.

Stability analysis of Katarni rice (Oryza sativa) derived lines under different sowing dates

Katarni is a non-basmati traditional aromatic rice (Oryza sativa L.) cultivar of Bhagalpur district of Bihar. This rice is weak strawed, traditionally tall type, late maturing and easily prone to lodging. Due to photosensitive nature, it matures very late only at the end of November and provide a narrow window for the sowing of wheat in farmers’ filed. An experiment was conducted at Bihar Agricultural University, Sabour, Bihar during 2018 and 2019 to develop a semi-dwarf and early maturing lines derived from crossing of Katarni with 3 semi-dwarf high yielding cultivars and were advanced to F5 generation. In this study, 54 derived lines of Katarni in F6 generation were studied on the basis of 14 morphological traits and yield stability was analysed in 4 environments. The environments were created by different sowing dates across two years (2018 and 2019) in a single location at Bihar Agricultural University, Sabour. Significant variability was found among the genotypes and four principal components (PC) identified, out of which two contributed 98.9% of total variation. Six advanced breeding entries were found to be significantly superior over parental checks for grain yield. Five Katarni derived were identified as highly stable genotypes on the basis of GGE and AMMI stability analysis. All four environments were constituted in two mega environments in which first one shared the best set of Katarni-derived lines. The promising advanced breeding lines with higher yield and stable performance can further be evaluated under multi-location testing for varietal release.

Morphophysiological Diversity and Haplotype Analysis of Saltol QTL Region in Diverse Rice Landraces for Salinity Tolerance

Rice is sensitive to salinity stress at both the seedling and reproductive stages. The present study used 145 rice genotypes comprising of 100 landraces and 45 advanced breeding lines collected from different regions of India. These genotypes were evaluated in hydroponics under control [electrical conductivity (ECe) ∼1.2 dS/m] and saline (ECe ∼10.0 dS/m) environments along with susceptible (IR29) and tolerant (FL478) checks. The stress susceptibility index for eight morphophysiological traits was estimated. Analysis of variance showed significant differences among the genotypes for all the parameters studied in control, stress and relative stress conditions. We identified 3 landraces (Kuttimanja, Tulasimog and IET-13713I) as tolerant and 14 lines as moderately tolerant to salt stress. Strong correlations in the morphological (root and shoot lengths) and physiological traits (shoot Na+, Ca2+ and Mg2+ contents, and Na+/K+ ratio) were observed under all the conditions. The hierarchical cluster analysis grouped the genotypes into five clusters, among which cluster II comprised salt-tolerant lines. Haplotyping of Saltol region using 11 simple sequence repeat markers on 17 saline tolerant and moderately tolerant lines was conducted. Markers AP3206F, RM10793 and RM3412b, located close to SKC1 gene (11.23‒12.55 Mb), displayed diverse allelic variations and they were not related to the FL478 type. In this region, tolerant lines like Kuttimanja, IET-13713I and Tulasimog have new alleles. As a result, these lines may be suitable candidates for novel genomic regions governing rice salinity tolerance. Salt-tolerance ability of Kuttimanja, Tulasimog and IET-13713I was validated in two years in three salinity stress environments. These promising lines can be used in breeding programs to broaden the genetic base of salinity tolerance in rice, and it may help to dissect key genomic regions responsible for salinity tolerance.

Neurofibromatosis type 1-associated optic pathway gliomas: pathogenesis and emerging treatments.

Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder associated with an increased risk of developing a variety of benign and malignant tumors. Fifteen to 20% of children with NF1 are diagnosed with an optic pathway glioma (NF1-OPG) before 7 years of age, and more than half of them experience visual decline. At present, no effective therapy is available for prevention, restoration, or even stabilization of vision loss in subjects affected by NF1-OPG. This paper aims to review the main emerging pharmacological approaches that have been recently assessed in preclinical and clinical settings. We performed a search of the literature using Embase, PubMed, and Scopus databases to identify articles regarding NF1-OPGs and their treatment up to July 1st, 2022. The reference lists of the analyzed articles were also considered a source of literature information. To search and analyze all relevant English articles, the following keywords were used in various combinations: neurofibromatosis type 1, optic pathway glioma, chemotherapy, precision medicine, MEK inhibitors, VEGF, nerve growth factor. Over the past decade, basic research and the development of genetically engineered mice models of NF1-associated OPG have shed light on the cellular and molecular mechanisms underlying the disease and inspired animal and human testing of several compounds. A promising line of research is focusing on the inhibition of mTOR, a protein kinase controlling proliferation, protein synthesis rate and cell motility that is highly expressed in neoplastic cells. Several mTOR blockers have been tested in clinical trials, the most recent of which employed oral everolimus with encouraging results. A different strategy aims at restoring cAMP levels in neoplastic astrocytes and non-neoplastic neurons, since reduced intracellular cAMP levels contribute to OPG growth and, more importantly, are the major determinant of NF1-OPG-associated visual decline. So far, however, this approach has only been attempted in preclinical studies. Stroma-directed molecular therapies - seeking to target Nf1 heterozygous brain microglia and retinal ganglion cells (RGCs) - are another fascinating field. Microglia-inhibiting strategies have not yet reached clinical trials, but preclinical studies conducted over the last 15 years have provided convincing clues of their potential. The importance of NF1-mutant RGCs in the formation and progression of OPGs also holds promise for clinical translation. The evidence of Vascular Endothelial Growth Factor (VEGF)- Vascular Endothelial Growth Factor (VEGFR) signaling hyperactivity in pediatric low-grade gliomas prompted the use of bevacizumab, an anti-VEGF monoclonal antibody, which was tested in children with low-grade gliomas or OPGs with good clinical results. Neuroprotective agents have also been proposed to preserve and restore RGCs and topical eye administration of nerve growth factor (NGF) has demonstrated encouraging electrophysiological and clinical results in a double-blind, placebo-controlled study. Traditional chemotherapy in patients with NF1-OPGs does not significantly ameliorate visual function, and its effectiveness in halting tumor growth cannot be considered a satisfactory result. Newer lines of research should be pursued with the goal of stabilizing or improving the vision, rather than reducing tumor volume. The growing understanding of the unique cellular and molecular characteristics of NF1-OPG, coupled with the recent publication of promising clinical studies, raise hope for a shift towards precision medicine and targeted therapies as a first-line treatment.

Genetic Dissection of Salt Tolerance and Yield Traits of Geng (japonica) Rice by Selective Subspecific Introgression

Salinity is a major factor limiting rice productivity, and developing salt-tolerant (ST) varieties is the most efficient approach. Seventy-eight ST introgression lines (ILs), including nine promising lines with improved ST and yield potential (YP), were developed from four BC2F4 populations from inter-subspecific crosses between an elite Geng (japonica) recipient and four Xian (indica) donors at the Institute of Crop Sciences, Chinese Academy of Agricultural Sciences. Genome-wide characterization of donor introgression identified 35 ST QTLs, 25 of which harbor 38 cloned ST genes as the most likely QTL candidates. Thirty-four are Xian-Geng differentiated ones with the donor (Xian) alleles associated with ST, suggesting differentiated responses to salt stress were one of the major phenotypic differences between the two subspecies. At least eight ST QTLs and many others affecting yield traits were identified under salt/non-stress conditions. Our results indicated that the Xian gene pool contains rich ‘hidden’ genetic variation for developing superior Geng varieties with improved ST and YP, which could be efficiently exploited by selective introgression. The developed ST ILs and their genetic information on the donor alleles for ST and yield traits would provide a useful platform for developing superior ST and high-yield Geng varieties through breeding by design in the future.

Association of High-Molecular-Weight Glutenin Subunits with Grain and Pasta Quality in Spring Durum Wheat (Triticum turgidum spp. durum L.)

Spring durum wheat is an important raw material for producing diverse products such as couscous, bulgur, bread, and pasta. The quality of the dough is significantly influenced by high-molecular-weight glutenins, the allelic status of which depends on the region and breeding program. In this study, a collection of 69 cultivars and promising lines of durum wheat were analyzed for the allelic state of Glu-A1 and Glu-B1 using SDS-PAGE and KASP PCR markers. Protein and gluten content, volume increase index, pasta breaking strength, general pasta estimation, SDS, and gluten index were measured for each accession based on a two-year field experiment in the Krasnodar region. The analysis revealed that the Glu-B1al, Glu-B1d, and Glu-B1z* alleles positively influence gluten index, with Glu-B1al increasing protein, gluten, and SDS content, whereas Glu-B1d decreased these traits. Glu-B1e, on average, decreased the gluten index and SDS value but did not affect protein or gluten content. The role of alleles affecting the gluten index and protein content in ensuring the quality of pasta in durum wheat breeding is discussed.

Mining natural genetic variations for nitrogen use efficiency utilizing nested synthetic hexaploid wheat introgression libraries

Wheat is grown on more than 240 million hectares globally, more than any other commercial crop. Variation for nitrogen-use efficiency (NUE) in wheat germplasm is very important as efficiency of nitrogen fertilizers use can have significant effect on overall consumption of N. In the present study we used nested synthetic hexaploid wheat introgression libraries to detect genetic variation associated with NUE and related traits. The libraries were genotyped with 9474 SNP markers and used for genome-wide association mapping. Significant phenotypic variation was observed for all measured and derived traits. We detected 10 Quantitative trait locus (QTL) and 19 marker-trait associations (MTAs) possibly involved in improving NUE. Of these, 5 QTL and 8 MTAs detected under nitrogen-limited conditions have potential for use in breeding to increase nitrogen-deficiency tolerance. Nitrate transporter genes collocated with detected MTAs showed significant changes in expression of TaNRT2 genes in response to N-starvation and N-recovery. The identified promising breeding lines with stable yield, better NUE and acceptable protein content may constitute an important genetic resource in improving NUE of modern wheat varieties.

Phenotypic and molecular identification of some blast resistance genes and biochemical responses of rice genotypes against rice blast pathogen

The current investigation was carried out to identify some isolates of Magnaporthe oryzae (anamorph: Pryicularia oryzae), the causal fungus of blast disease, and to assess their virulence against monogenic lines and other rice genotypes. In addition, the biochemical changes after inoculation with blast pathogen were evaluated. The linked markers to blast resistance genes were identified, the potential gene(s) operating in genotypes were assessed at field conditions. Twenty-seven isolates were identified as six race groups; the ID group was highly distributed, followed by group IC. Resistance genes Pii (IRBLi-F5), Piz-5 (IRBLz5-CA (R) and Pit (IRBLt- K59) were completely resistant to test races. New promising lines i.e. GZ10686-2-1-3-4, GZ10848-1-2-2-1, GZ11190-3-13-4-1, and GZ11312-3-3-1-3 were resistant for test races under artificial inoculation, and induced the highest activity for defense-related enzymes i.e. phenylalanine ammonia-lyase (PAL), chitinase, and the test antioxidant enzyme i.e. peroxidase (POX) and ascorbate peroxidase (APX). Molecular analysis confirmed the existence of genetic variation and the similarity percentage among genotype pairs was as low as 10%. The more genes a specific genotype was carrying, the more resistance and durability are expected. There was collinearity between the superiority of promising lines GZ10848-1-2-2-1 and GZ11190-3-13-4-1 and their respective number of blast-linked genes where they have the highest number of blast-linked genes. Under field evaluation, the advanced promising lines performed well in grain yield compared to the cultivated varieties, especially GZ10848-1-2-2-1, and GZ11190-3-13-4-1, and resistance to blast disease.

Breeding Cowpea for Adaptation to Intercropping for Sustainable Intensification in the Guinea Savannas of Nigeria

Cowpea is a multifaceted crop; however, considerable challenges affect the production of this crop despite its comparatively better adaptation to harsh environments. Most smallholder farmers in West Africa cultivate this crop in intercropping systems where its low plant population does not allow the full expression of the cultivars’ yield potential. This is because most varieties currently grown in intercrop have been developed in and for monocropping, although some breeding programs recently have focused on intercrop systems. This study, therefore, aimed to evaluate the performance of some newly developed cowpea breeding lines for adaptation to intercropping systems. Firstly, an on-station field experiment was conducted in 2018. The selected promising lines and a standard check were evaluated in three locations in an intercropping system and on-farm trials. Significant differences were observed among the cowpea genotypes for all the traits measured. Two improved lines, UAM14-122-17-7 and UAM14-123-18-3, had superior grain and fodder yields under sole and intercropping systems and in different agroecological systems, revealing their adaptability. Based on our findings, UAM14-122-17-7 and UAM14-123-18-3 are recommended for a cereal-cowpea mixture because they are adapted to intercropping and produce high-grain yield under intercrop and sole-cropping systems.

Development of semidwarf breeding line with shattering resistance and preharvest‐sprouting resistant in buckwheat (Fagopyrum esculentum)

AbstractAn important breeding issue in buckwheat is to increase its resistance to lodging, which can result in the loss of yield and quality of buckwheat foods. We developed the semidwarf buckwheat ‘Kyukei 50’, which has a short plant height and a strong lodging resistance. The internode length of ‘Kyukei 50’ was shorter than that of the summer‐sown standard variety ‘HITACHIAKISOBA’. Progeny analysis revealed that the semidwarf trait was dominated by at least one recessive gene. Compared with ‘HITACHIAKISOBA’, in ‘Kyukei 50’, the time of maturation was earlier, and the pre‐harvest sprouting resistance was the same, indicating that ‘Kyukei 50’ is suitable for sowing in both spring and summer. ‘Kyukei 50’ exhibits the ‘green flower type’ shattering resistance trait and, therefore, has a thick pedicel; breaking tensile strength is approximately two‐fold stronger than that of ‘HITACHIAKISOBA’. The yield of ‘Kyukei 50’ is the same as that of ‘HITACHIAKISOBA’. In addition, the lowest seed height of ‘Kyukei 50’ was >17 cm. These results indicate that the ‘Kyukei 50’ is a promising breeding line for lodging resistance and loss of harvesting machinery.

Assessment of the Power Equipment State by Measuring Dielectric Absorption Currents

The need to operate electrical devices the design capabilities of which have been exhausted almost completely under the conditions of more stringent reliability requirements gives rise to increased attention to the development and research of methods for diagnosing the power equipment state. This problem acquires not only a scientific interest, but also practical significance, which follows, in particular, from the mass-scale use of power transformers for operating voltages above 35 kV. One of promising development lines is the method of constructing dielectric absorption spectra, which is based on using the capabilities of isothermal depolarization current measurements. In this case, the information that accumulates as a result of the insulation system’s dielectric medium polarization as a certain number of loosely coupled charges displaced from their locations is adequate (equivalent) to the information obtained as a result of depolarization when measuring the return voltage (RV) value. Owing to the above-mentioned adequacy, it is possible to use the quantity tI(t) as a parameter for monitoring the state of the power equipment insulation system. The spectrum construction algorithm presented in the article is similar to the algorithm for constructing the RV spectrum, but is produced in the course of computer-aided processing of measurement results using the time windows that specify the insulation gap polarization time interval. As a result, it becomes possible not only to produce the dielectric absorption spectrum, but also to calculate the values of the main parameters characterizing the gap state.