(1) Background: Curcuma caesia Roxb. is a high valued crop which is extensively used in pharmaceuticals, flavour and fragrances. C. caesia is recognised as an endangered species due to its extensive collection from the wild through human intervention. Therefore, to prevent the species from extinction, it is very necessary to conserve and cultivate this plant species for the sustainable availability of the raw material. (2) Methods: In the present plant breeding programme, a multi-year study was performed for the identification of superior genotypes which will help in conservation. To fulfil this objective, a total of 135 accessions of C. caesia were collected from different regions of India and were set up for experimental selection trial for three years (2016–2018). After proper evaluation of the genotypes based on six agronomical traits, five high-yielding genotypes were identified which underwent multilocation trial for two years (2019 and 2020). The stability analysis using the Eberhart–Russell method, AMMI and GGE biplot were used to study the consistency of the genotypes in varied environments compared with the check variety. (3) Results: Analysis of variance indicated significant genotype and environment interaction for the yield traits, i.e., dry rhizome recovery, rhizome yield and essential oil yield. The coefficient of variation (CV) was highest for tillers per plant (21.76) and lowest for the plant height (4.93). All the results clearly demonstrated Jor Lab KH-2 as the highest yielding and stable genotype in varied environments compared with the check variety and other selected genotypes. (4) Conclusions: This genotype was then submitted to ICAR-NBPGR, New Delhi, for germplasm registration and received its confirmation vide registration number INGR 21159. This genotype will greatly benefit the breeders and will also help in the conservation of this endangered species. This is the first report on the identification and registration of a high-yielding variety of C. caesia.

Solanum khasianum is a medicinally important plant that is a source of steroidal alkaloids ‘solasodine.’ It has various industrial applications, including oral contraceptives and other pharmaceutical uses. The present study was based on 186 germplasm of S. khasianum, which were analyzed for the stability of economically important traits like solasodine content and fruit yield. The collected germplasm was planted during Kharif 2018, 2019, and 2020 in RCBD with three replications at the experimental farm of CSIR-NEIST, Jorhat, Assam, India. A multivariate approach for stability analysis was applied to identify stable germplasm of S. khasianum for economically important traits. The germplasm was analyzed for additive main effects and multiplicative interaction (AMMI), GGE biplot, multi-trait stability index, and Shukla’s variance which were evaluated for three environments. The AMMI ANOVA revealed significant GE interaction for all the studied traits. The stable and high-yielding germplasm was identified from the AMMI biplot, GGE biplot, Shukla’s variance value, and MTSI plot analysis. Lines no. 90, 85, 70, 107, and 62 were identified as highly stable fruit yielders while, lines no. 1, 146, and 68 were identified as stable high solasodine lines. However, considering both traits, i.e., high fruit yield and solasodine content, MTSI analysis was performed which showed that lines 1, 85, 70,155, 71, 114, 65, 86, 62, 116, 32, and 182 could be used in a breeding program. Thus, this identified germplasm can be considered for further varietal development and could be used in a breeding program. The findings of the present study would be beneficial for the S. khasianum breeding program.