Interest in belowground plant growth is increasing, especially in relation to arguments that shallow-rooted cultivars are efficient at exploiting soil phosphorus while deep-rooted ones will access water at depth. However, methods for assessing roots in large numbers of plants are diverse and direct comparisons of methods are rare. Three methods for measuring root growth traits were evaluated for utility in discriminating rice cultivars: soil-filled rhizotrons, hydroponics and soil-filled pots whose bottom was sealed with a non-woven fabric (a potential method for assessing root penetration ability). A set of 38 rice genotypes including the OryzaSNP set of 20 cultivars, additional parents of mapping populations and products of marker-assisted selection for root QTLs were assessed. A novel method of image analysis for assessing rooting angles from rhizotron photographs was employed. The non-woven fabric was the easiest yet least discriminatory method, while the rhizotron was highly discriminatory and allowed the most traits to be measured but required more than three times the labour of the other methods. The hydroponics was both easy and discriminatory, allowed temporal measurements, but is most likely to suffer from artefacts. Image analysis of rhizotrons compared favourably to manual methods for discriminating between cultivars. Previous observations that cultivars from the indica subpopulation have shallower rooting angles than aus or japonica cultivars were confirmed in the rhizotrons, and indica and temperate japonicas had lower maximum root lengths in rhizotrons and hydroponics. It is concluded that rhizotrons are the preferred method for root screening, particularly since root angles can be assessed.

The rapid progress in rice genotyping must be matched by advances in phenotyping. A better understanding of genetic variation in rice for drought response, root traits, and practical methods for studying them are needed. In this study, the OryzaSNP set (20 diverse genotypes that have been genotyped for SNP markers) was phenotyped in a range of field and container studies to study the diversity of rice root growth and response to drought. Of the root traits measured across more than 20 root experiments, root dry weight showed the most stable genotypic performance across studies. The environment (E) component had the strongest effect on yield and root traits. We identified genomic regions correlated with root dry weight, percent deep roots, maximum root depth, and grain yield based on a correlation analysis with the phenotypes and aus, indica, or japonica introgression regions using the SNP data. Two genomic regions were identified as hot spots in which root traits and grain yield were co-located; on chromosome 1 (39.7–40.7 Mb) and on chromosome 8 (20.3–21.9 Mb). Across experiments, the soil type/ growth medium showed more correlations with plant growth than the container dimensions. Although the correlations among studies and genetic co-location of root traits from a range of study systems points to their potential utility to represent responses in field studies, the best correlations were observed when the two setups had some similar properties. Due to the co-location of the identified genomic regions (from introgression block analysis) with QTL for a number of previously reported root and drought traits, these regions are good candidates for detailed characterization to contribute to understanding rice improvement for response to drought. This study also highlights the utility of characterizing a small set of 20 genotypes for root growth, drought response, and related genomic regions.

No abstract

Aims: Plumbago indica is a medicinal plant widely grown in the tropics and temperate region to use in traditional systems of medicine. Different parts of this plant are used to treat rheumatoid arthritis, dysmenorrhea, cancer, leprosy, syphilis, rheumatism, paralysis, headache, leukoderma, enlarged glands, scabies, ophthalmia, dyspepsia, haemorrhage, piles, flatulence, loss of appetite etc. Various kinds of researches were carried out in different countries on propagation and pharmacology of this medicinal plant. Scientifically proven data were concentrated on this paper to facilitate reliable convenience data source and encourage further studies. Methodology: Scientific data published on full papers, abstracts about morphology, growth, propagation, traditional medicinal uses and pharmacology of P. indica over 70 years (1949-2020) by researchers in different countries were collected and categorized under suitable topics. Results: According to literature P. indica leaves, stems, roots contain phytochemical compound that are responsible for its medicinal properties. Tissue culture of this plant can be uses as effective propagation method to fulfill the increasing demand of raw materials (dried plant parts) for medicinal preparations as well as preserve the plant in their natural habitat. Value: P. indica is used to treat vast range of diseases in traditional medicinal systems in different countries and currently pharmacological experiments are conducting to prove it scientifically. Plumbagin present in P. indica roots was already identified as a potential anti-cancer agent and subjected to more research interest. Therefore this review article helps new researchers to get wide knowledge about the plant and its pharmacology.

No abstract