In the North Eastern Himalayan region (NEHR) of India, maize is an important food crop. The local people cultivate the maize landraces and consume them as food. However, these landraces are deficient in β-carotene content. Thus, we aimed to incorporate the crtRB1 gene from UMI285β⁺ into the genetic background of the NEHR maize landrace, Yairipok Chujak (CAUM66), and thereby enhance the β-carotene content through marker-assisted backcrossing (MABC). In this regard, we backcrossed and screened BC₁F₁ and BC₂F₁ plants possessing the heterozygous allele for crtRB1 and then screened with 106 polymorphic simple sequence repeat (SSR) markers. The plants having maximum recurrent parent genome recovery (RPGR) were selected in each generation and selfed to produce BC₂F₂ seeds. In the BC₂F₂ generation, four plants (CAUM66-54-9-12-2, CAUM66-54-9-12-11, CAUM66-54-9-12-13, and CAUM66-54-9-12-24) having homozygous crtRB1-favorable allele with maximum RPGR (86.74–90.16%) were selected and advanced to BC₂F₃. The four selected plants were selfed to produce BC₂F₃ and then evaluated for agronomic traits and β-carotene content. The agronomic performance of the four lines was similar (78.83–99.44%) to that of the recurrent parent, and β-carotene content (7.541–8.711 μg/g) was on par with the donor parent. Our study is the first to improve the β-carotene content in NEHR maize landrace through MABC. The newly developed lines could serve as potential resources to further develop nutrition-rich maize lines and could provide genetic stock for use in breeding programs.

Nanotechnology has application potential and prospects in plant pathology in many different aspects viz. direct application in foliage, seeds or soil for plant disease management along with accurate, reproducible, quantitative, reliable, specific, robust, and stable results. Extracellularly and intracellularly synthesis of NPs is carried out using microbes. Detection of plant pathogen plays an important role in successful management of many plant diseases, allowing the effective controlling of disease at various stages of disease development. By virtue of their small size, nanoparticles have exclusive chemical, photosensitive and electrical properties and offer improved surface-to-volume ratios. Nano particles finds application in regulation of pathogen concentration, its severity, rate of infection, and percentage of bacteria and fungi, viruses, actinomycetes and other pathogens. Nanoparticles causes induction of systemic resistance, reduction of cellular factors, inhibition of DNA replication, suppression of polymerase activity and lowering of infection rate. Emergence of nano particles has enormous concern in agriculture in relation to environment. Even though some of the nanoparticles have varied negative effect, which might lead to degradation of root membrane, remodeling agriculture and successful management of plant pathogens would not be possible without nanotechnology which directly reflects positively on the sustenance of food production and fulfil the increasing demands of food production in an efficient and cost-effective way. Moreover, nanotechnology plays important role in pathogen sensing and control and provides a remedy to the emerging agricultural challenges. Profound research studies, regarding the possible aspects of nanotechnology in plant pathology, is being carried out for exploring an economic, eco-friendly stabilized nanomaterials for effective management of plant diseases in the long run.

The glycemic index (GI) of rice is a complex trait, affected by amylose content (AC), size, and packaging of starch granules (SGs). In this study, the electron microscopy results of starch morphology of nine rice genotypes showed varying AC (6.93–36.9%), and the predicted GI (pGI: 41.07–82.46) in relation to genetic factors revealed that smaller SG surface area (20.06 µm²) and irregular morphology (Hap 3-3 P-11, pGI = 41.07) were associated with a lower pGI, while larger SG surface area (47.68 µm²) and spherical structure were associated with a higher pGI (NON-HAI, pGI = 82.46). The expression of starch biosynthesis and packaging-related genes (OsSSIIb, OsSSIIc, OsSBEIIa, OsISA1, OsISA3, OsGBP, OsFLO6, and OsBT1) revealed downregulation of OsGBP and OsISA3 genes in low pGI lines IRRI-147 (pGI = 56.2) and Hap 3-1-p-18 (pGI = 41.79), respectively, while higher levels of expression of the OsBT1 gene in Makro (pGI = 59.06) and OsSSIIb in Swarna (pGI = 58.06) were observed. All these genotypes had similar AC (~30%), but the difference in expression pattern was correlated with starch granule morphology, suggesting its role in influencing pGI. Further, analysis of allelic variation in eight starch-related genes across 20 rice genotypes showed that allelic variants of only OsGBP were correlated with AC, where allele group 2 showed lower AC (9.62%), while all other allele groups showed consistently high AC (22–24%). These findings underscore the critical role of starch granule morphology and OsGBP allelic variation in determining AC and GI, providing actionable insights for developing low GI rice varieties using tools like CRISPR.