Rice (Oryza sativa L.) production on acidic drylands needs optimization through breeding to develop drought-resistant cultivars. The rice cultivar Inpago-5 showed moderate tolerance to drought stress. However, further enhancing this tolerance can proceed by precise gene editing of the DREB (dehydration-responsive element binding) gene, utilizing the CRISPR (clustered regularly interspaced palindromic repeats) /Cas9 system. The presented study aimed to engineer the single-guided RNA (sgRNA) targeting the DREB gene in rice cultivar Inpago-5 using the CRISPR/Cas9 approach. The use of the pRGEB32 plasmid harboring the Cas9 gene helped facilitate the cloning of sgRNA-DREB through the Golden Gate cloning technique and heat shock transformation. The sgRNA-DREB confirmation succeeded through colony PCR (polymerase chain reaction), followed by plasmid isolation and subsequent validation using PCR with specific primers and sequencing primers targeting the pRGEB32 vector. The latest analysis revealed the pRGEB32-sgDREB_sg1 and pRGEB32-sgDREB_sg2 transformed bacteria proliferated on LB+Kanamycin selection media, indicating successful insertion of sgRNA-DREB into the pRGEB32 plasmid. The verification through colony and plasmid PCR with specific primers confirmed the presence of a 425-bp amplicon. Sequencing data showed the correct insertion of sgRNA-DREB sequences at the designated site.

Keywords: Rice (O. sativa L.), cultivar Inpago-5, plant breeding, CRISPR/Cas9, gene editing

Key findings: The gene encoding rice (O. sativa L.) drought tolerance DREB4 succeeded integration into the pRGEB32 vector, with the sgRNA-DREB accurately inserted at the targeted site.

Heterosis and inbreeding depression are key considerations in potato breeding, particularly in regions with limited resources. Heterosis (F₁) and inbreeding depression (F₂) investigations ensued in 2022–2024 in eight different potato (Solanum tuberosum L.) hybrids generated from true potato seeds in Abbottabad and Battakundi, Pakistan. A randomized complete block design experiment transpired with three replications. The analysis of variance revealed significant differences among the potato hybrids for all traits, except the tuber germination percentage, signifying a substantial level of genetic variability. The Cardinal × Roko hybrid has demonstrated exceptional hybrid vigor for the number of medium tubers plot^-1, with high estimates of relative heterosis (61.78%), heterobeltiosis (61.78%), and standard heterosis (86.01%). The negative inbreeding depression observed for all studied traits, ranging from –0.364% to –187.67%, indicates inbreeding has significantly impacted the performance of hybrids. The noted positive correlations among potato traits provide valuable insights for breeding programs. Results concluded the cross combinations, Cardinal × Roko and Kuroda × Burna, exhibited significant and high heterotic values for the number and weight of medium tubers plot^-1, while desirable negative heterosis for days to maturity. It confirms these crosses have strong potential for release as new potato hybrids. Further evaluation of these hybrids in future breeding strategies can probe ultimate potential for resilience, yield, and other important traits.

Keywords: Potato, true potato seed, heterosis, inbreeding depression, Cardinal × Roko, Kuroda × Burna

Key findings: Given the heterotic effects, the hybrids’ cross combinations demonstrated superior mean performance for the evaluated traits compared with their parental cultivars. Cardinal × Roko and Kuroda × Burna were the best crosses due to the high number and weight of medium tubers plot^-1, positive heterosis, and desirable negative heterosis for days to maturity. Additionally, Battakundi has become a valid ideal environment for potato cultivation and future breeding programs.

The success of hybrid maize (Zea mays L.) breeding depends on understanding the combining ability effects of the inbred lines. The study aimed to evaluate the general combining ability (GCA), specific combining ability (SCA), and heterotic effects in yellow maize for various traits. Ten inbred lines’ crossing with three testers used the line-by-tester mating scheme. The resulting 30 F₁ hybrids underwent evaluation against two check genotypes in a randomized complete block design (RCBD) with three replications during the kharif growing season of 2021 at the Cereal Crop Research Institute (CCRI), Nowshehra, Pakistan. Significant heterotic and combining effects were evident for the studied traits. Inbred lines YL-02 and YL-06 showed significant positive GCA for ear length, 100-grain weight, and grain yield. The F₁ hybrids YL-02 × YD-04 (8209.6 kg ha^-1) and YL-01 × YL-07 RC (6979.6 kg ha^-1) revealed maximum grain yield and significant positive SCA effects, indicating potential for yield improvement. Estimates of SCA were greater than GCA for all the studied traits, signifying the importance of the non-additive gene action in the inheritance of studied traits. Based on combing ability effects and yield performance, the F₁ crosses YL-02 × YD-04 and YL-01 × YL-07 RC are desirable for future breeding programs.

Keywords: Maize (Z. mays L.), hybrids, mean performance, combining ability, heterosis, heterobeltiosis, grain yield, gene action.

Key findings: The maize (Z. mays L.) inbred lines YL-01, YL-02, and YL-06 emerged with desirable and significant GCA effects. The F₁ hybrids YL-02 × YD-04 and YL-01 × YL-07 RC exhibited with significant SCA effects and maximum grain yield. These parents and hybrids could be beneficial in future hybridization programs of yellow maize.

Wheat (Triticum aestivum L.) is the most widely cultivated cereal worldwide, a staple food for 40% of the world’s population that contributes 20% of total dietary requirements. Yellow dwarf viruses are viruses affecting the grain yield and its quality and damaging the cereal crops economically. Yellow dwarf viruses are the most economically important plant viruses impacting cereal production worldwide, which include viruses from the genus Luteovirus BYDV-PAV, MAV, and Polerovirus CYDV-RPV. The Cereal Yellow Dwarf Virus (CYDV-RPV) is one of the most dangerous YDV viral species. Barley/cereal yellow dwarf viruses cause yellow dwarf disease, which is a continuous risk to cereal crop production globally. These viruses cause leaf yellowing and stunting, resulting in yield reduction of up to 80%. They are the most critical viral diseases of cereals worldwide. They have a wide host range, which includes wheat, barley, oats, and over 150 grass species. These viral infections have the potential to spread epidemics in Uzbekistan’s wheat fields during specific seasons and play a crucial role in the epidemiological process. Using the KibrayT1 isolate of the CYDV-RPV strain, the following study aimed to determine the prevalence of CYDV-RPV in wheat fields in the District of Kibray, Tashkent Region, Uzbekistan. The use of reverse transcription-polymerase chain reaction succeeded in making the diagnosis.

Keywords: Wheat (T. aestivum L.), cereal yellow dwarf virus (CYDV), RT-PCR, CP gene, phylogenetic analysis, KibrayT1

Key findings: The CYDV-RPV isolate detection was successful by RT-PCR in wheat (T. aestivum L.). The determination of the nucleotide sequence of the coat protein gene prevailed in this isolate. The phylogenetic analysis revealed its close relatedness to the Jordan CYDV-RPV isolate ‘Jordon’ (HQ206716.1).

Based on the Central Statistics Agency, Indonesia, rice (Oryza sativa L.) production decreased by 2.63 million tons (7.75%) in 2019 compared to 2018, and that could refer to the decrease in rice-growing areas. Therefore, the rice crop area requires enhancement by the utilization of suboptimal tidal swamp lands. However, the heavy iron content in swamp lands is a limiting factor to rice growth. The study aimed to select the iron stress-tolerant rice genotypes by using the effective SSR markers. The arrangement of treatments was a factorial (4×4) completely randomized design with six replications. The first factor was four rice strains (Siam Saba, Siam Tanggung, lNPARI 34, and Ciherang), and the second factor was two iron concentrations (0 and 1,600 ppm) of sulfate heptahydrate solution. The ISC analysis showed the rice genotype Siam Saba appeared to be tolerant to Fe2SO4 stress (1,600 ppm). The SSR marker amplification revealed the primers RM8213, RM252, and RM335 proved more informative and can be effective for genetic studies.

Keywords: FRO gene, genetic study, growth traits, iron tolerance, rice (O. sativa L.), SSR markers, swamp lands

Key findings: The concerned study produced the tangible information on the rice (O. sativa L.) strains resistance to iron stress based on physiological and genetic characteristics. This information will help the breeders in designing breeding strategies for developing iron-tolerant genotypes for cultivation on tidal swamp lands.

CRISPR/Cas9-mediated genome editing has become a common technology for gene manipulation in plant gene research and crop improvement. Studies have developed technologies with Agrobacterium-mediated transient expression of genome-editing machinery to generate transgene-free plants with an edited locus. This study examined the combined effect of short-term (three-day) antibiotic selection and heat treatment (24 hours at 37 °C) on genome editing efficiency in two different systems. Both systems targeted the same two genes, PDS and MAR1, in tobacco. The first system employed developmental regulator genes (DRs) inducing shoot formation to select plants with transient foreign gene expression. The other relied on phytohormone-induced shoot formation. The DRs, including the cytokinin-producing ipt gene, induced tobacco shoot formation after Agrobacterium-mediated transient expression. The combined treatment and heat treatment alone reduced the shoot formation, but the three-day selection alone did not. Interestingly, the combined treatment elevated the percentage of transgene-free mutant shoots to 7.6% as compared to 1.2% with heat treatment alone in ipt-induced shoots. In the shoots induced by the externally added phytohormone, the percentages of transgene-free mutant shoots were 2.8%, 5%, and 7.7% after three-day antibiotic selection alone, heat treatment alone, and the combined treatment, respectively.

Keywords: Genome editing, transgene-free, mutation, heat treatment, antibiotic selection

Key findings: The study investigated the impact of combining three-day antibiotic selection and 24-hour heat treatment on CRISPR/Cas9-mediated genome editing in a model plant, tobacco. The combined treatment significantly increased the percentage of transgene-free mutant shoots compared with individual treatments, regardless of shoot induction modes: transient expression of morphogenic inducer or optimized phytohormones in a medium.

Summary: The use of silicon is an option for reducing the adverse effects of water deficit conditions. Dendrobium nobile Lindl. is a native orchid from Lampung, Indonesia, and one of the most widespread ornamental members of the family Orchidaceae. It contains alkaloids, flavonoids, and terpenoids, which are beneficial as antiviral compounds. Characterization succeeded in determining the potential variations in its genetic stability and phytochemical properties through DNA nucleotide sequence polymorphism analysis using the random amplified polymorphic DNA (RAPD). The presented research involved eight accessions of D. nobile collected from the Liwa Botanical Garden, West Lampung, Indonesia. The screening used five primers, viz., OPA-01, OPA-07, OPN-07, OPC-16, and OPD-08. The study revealed a PIC value (≥ 0.3), indicating that these molecular markers were more informative. The amplification process produced 107–134 DNA bands, including 17 polymorphic bands ranging from 200–1000 bp. The polymorphism rate for each primer ranged from 0.31 to 0.40. Phylogenetic analysis grouped the accessions into two clusters with coefficient values at >0.85 and >0.9, while similarity indices were 0.33 and 0.55, respectively. The accessions’ further dividing into two subclusters comprised subcluster I (D2, D5, D1, D7, D4, and D8) and subcluster II (D3), based on habitat differences and environmental factors linked to their domestication. The PCR-RAPD proved more effective in characterizing the genetic stability in relation to antiviral phytochemicals.

Keywords: Dendrobium nobile Lindl., Orchidaceae, genetic stability, phytochemical and antiviral properties, RAPD, polymorphism

Key findings: The RAPD technique was evidently more effective in characterizing the genetic stability related to antiviral properties of the Dendrobium nobile accessions in Lampung, Indonesia.

Knowledge about germplasm diversity is an invaluable aid in crop improvement strategies. The following research aimed to study the diversity of 53 mustard (Brassica rapa) genotypes. The study had a randomized complete block design with three replications, implemented at the Genetics and Plant Breeding Department experimental field of Bangabandhu Sheikh Mujibur Rahman Agricultural University. The collected germplasms came from the said university and the Bangladesh Agricultural Research Institute. Different multivariate analysis techniques used help classify genotypes across 21 studied characteristics, with all the genotypes grouped into seven clusters. Among the seven clusters, Cluster III had the most genotypes (12) and Cluster IV the least (1). Cluster VII showed the highest intra-cluster distance, and Cluster IV the lowest. The largest inter-cluster distance was between clusters IV and VII, and the smallest was between clusters I and III. Selecting genotypes from clusters with the greatest distances could enhance genetic diversity and heterosis. Genotypes from clusters with moderate to high inter-cluster distances and medium to high yields could be applicable for desirable segregants. Specifically, genotypes G₂, G₁₂, G₁₇, G₃₃, and G₄₄ from Cluster I; G₁, G₁₀, G₃₈, and G₄₀ from Cluster II; G₈, G₁₃, G₂₇, and G₄₃ from Cluster III; G₅₁ from Cluster IV; G₂₁, G₃₄, and G₅₂ from Cluster V; G₂₅ and G₃₇ from Cluster VI; and G₃ and G₄₁ from Cluster VII would be favorable selections as superior parents for hybridization programs.

Keywords: Oil seed, mustard, genetic diversity, morphological characteristics, cluster analysis, and D2 statistic

Key findings: The highest genetic divergence emerged between clusters IV and VII, suggesting that selecting genotypes from these clusters could enhance heterotic F₁ generation and diversity in segregating generations.

The following study comprised the combining ability in parental genotypes and the inheritance of yield-related traits in F₁ hybrids of the Pima cotton (Gossypium barbadense L.). The cotton cultivars, Surkhon-9 and Termiz-32, were notably the high-level donor parental genotypes in seed cotton yield and play a vital role in the development of high-yielding cotton cultivars. In all cultivars (σ2si>σ2gi), the dominant role of non-additive variances was evident in managing the seed cotton yield. Study results showed the cultivar Termez-32 can become a donor parent in developing new cultivars with numerous bolls per plant. By comparing the GCA and SCA variances of cotton cultivars, the bolls per plant reflected the control of non-additive genes (σ2si>σ2gi) in cultivars Surkhon-9, Duru Gavhar, and Surkhon-10. In cultivars Termiz-32 and Bukhoro-7, the bolls per plant had the additive genes (σ2si<σ2gi) managing them. Thus, the inheritance of the seed cotton yield per plant and the number of bolls traits occurred mainly with the positive superdominance in the F₁ cross combinations. An outcome of the presented study revealed the development of the new Pima cotton cultivar ‘Guzor.’

Keywords: Pima cotton (G. barbadense L.), cultivars, diallel crosses, combining ability, inheritance, dominance, yield-related traits

Key findings: Results revealed that Pima cotton (G. barbadense L.) cultivars, Termiz-32 and Bukhoro-7, can be desirable for improving the seed cotton yield, while Surkhon-9 and Termiz-32 can be useful for enhancing bolls per plant of cotton. The said breeding material can be beneficial in the development of high-yielding Pima cotton cultivars.

Diallel analysis undertakes the adequate capture of the interaction of genes contributing to traits’ variation by the general (GCA) and specific combining ability (SCA) effects. However, in reality, the genes’ interaction can be more complex, involving epistatic interactions and pleiotropy, which are unaccounted for in the traditional diallel analysis. Therefore, the presented work sought to study the combining ability in wheat genotypes widely planted in Uzbekistan. The mode of inheritance as studied through combining ability included the vegetation period, plant height, vitreousity, grain weight per ear, 1000-kernel weight, grain yield, and productive accumulation in 4 × 4 F₁ diallel hybrids of wheat. The analysis of variance indicated significant differences among the parental genotypes and their F₁ hybrids in the GCA, SCA, and reciprocal effect of the previously mentioned characters on grain size. Consequently, it helped determine the grain and cultivar quality, as well as the genetic strength of the grain. For management of the grain yield, the GCA and reciprocal effects played major roles compared with the SCA effects. Significant variances due to GCA and SCA showed the predominance of additive, epistatic, and dominant gene effects in controlling the inheritance of the wheat’s studied traits.

Keywords: Bread wheat (T. aestivum L.), F₁ hybrids, diallel analysis, combining ability, additive, epistatic, dominant gene effects, morphological and yield traits

Key findings: Significant variances due to GCA and SCA showed greater genetic variability in the F₁ populations and the predominance of additive, epistatic, and dominant gene effects in managing the inheritance of morphological and yield traits in bread wheat (T. aestivum L.).