Biologically important curcuminoids viz curcumin, demethoxycurcumin, and bisdemethoxycurcumin in turmeric rhizome have several health benefits. Pharmaceutical industries synthesize curcuminoids manipulating gene expressions in vitro or in vivo because of their medicinal importance. In this experiment, we studied the gene expressions involved in the curcuminoid biosynthesis pathway in association with curcuminoid yield in turmeric rhizome to study the impact of individual gene expression on curcuminoid biosynthesis. Gene expressions at the different growth stages of turmeric rhizome were association tested with respective curcuminoid contents. Gene expression patterns of diketide-CoA synthase (DCS) and multiple curcumin synthases (CURSs) viz curcumin synthase 1 (CURS1), curcumin synthase 2 (CURS2), and curcumin synthase 3 (CURS3) were differentially associated with different curcuminoid contents. Genotype and growth stages showed a significant effect on the gene expressions resulting in a significant impact on curcuminoid balance in turmeric rhizome. DCS and CURS3 expression patterns were similar but distinct from CURS1 and CURS2 expression patterns in turmeric rhizome. DCS expression had a significant positive and CURS3 expression had a significant negative association with curcumin, demethoxycurcumin, bisdemethoxycurcumin, and total curcuminoid in turmeric rhizome. CURS1 expression had a negative association with curcumin whereas CURS2 expression showed a positive association with demethoxycurcumin. The effects of DCS and CURS expressions are not always positive with different curcuminoid contents in turmeric rhizome. DCS expression has a positive and CURS3 expression has a negative association with curcuminoids. CURS1 and CURS2 are also associated with curcumin and demethoxycurcumin synthesis. This mechanism of co-expression of diketide-CoA synthase and multiple curcumin synthases in turmeric rhizome has a significant effect on curcuminoid balance in different turmeric cultivars. Further experiment will explore more insights; however, association-based test results from this experiment can be useful in improving curcuminoid yield in turmeric rhizome or in vitro through the application of genetic engineering and biotechnology. Associating gene expressions with curcuminoid biosynthesis in turmeric

Twelve amaranth accessions were evaluated in a randomized complete block design with three replications in the research field of the Institute of Agriculture and Animal Science, Lamjung, Sundarbazar, Lamjung, Nepal from March to July 2021 to assess the phenotypic diversity. Principal Component Analysis (PCA) showed that only two principal components were significant with their eigenvalues >1 and combinedly accounted for 88.3% of the total variance. PC1, which explained 71.9% of the variance, was highly and positively contributed by days to 50% inflorescence, plant height, leaf length, leaf width, petiole length, 1000 seed weight, and grain yield. PC1 was negatively affected by the number of primary branches per plant and the number of leaves per plant. PC2, which explained 16.4% of the variance, distinguished plants with high number of leaves and a higher inflorescence length. The accessions were grouped into 4 clusters. Cluster 2 had the greatest intracluster distance (D² = 13.19), while Cluster 3 and 4 had the greatest intercluster distance (D² = 21.73), followed by Cluster 2 and 3 (D² = 17.37). Cluster 1 had the highest number of leaves per plant and the lowest yield. Cluster 2 had the maximum grain yield and plant height. Cluster 3 had the lowest inflorescence length, and cluster 4 had the highest leaf length and 1000 seed weight.

Field trials of rice and bean dynamic mixtures were carried out in low input and hill farming systems of Nepal from 2019 to 2021 to improve productivity and resilience. The rice trials were conducted in two locations (Jumla and Lamjung) and those on bean in Jumla, using a randomized complete block design with three replications. Dynamic mixtures were constructed from landraces, improved varieties and breeding lines for both crops. A total of 48 bean entries were used in Jumla, whereas 56 and 66 rice entries were used to make location-specific dynamic mixtures in Lamjung and Jumla, respectively. They were formed by mixing diverse varieties as a strategy to maintain a broad genetic base. Farmers (men and women) and technicians selected from the most complex mixture and the selections were added to the trials starting from second year. In rice, some mixtures and selections from the mixtures gave grain yield comparable to the improved check and higher than the local checks. In the case of bean, differences between entries were not significant but some of the selections received a high preference score. Overall, the dynamic mixtures appear as a reliable material for sustainable increase in yield in the low input and hill farming system of Nepal.