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Maize (Zea mays L.) is one of the important cereal crops in the world and is the third largest grown cereal crop in India. Field surveys conducted in 2013-15 recorded stalk rot incidence of 28–35% in southern states of India. The typical symptoms were observed after pollination with the drying of the lower leaves and eventually entire plant wilted prematurely, lower internodes turned in to grey-green color and stalks are hollow and weak leading to the lodging of the plant. Stalk rot associated pathogen was isolated on PDA medium. Out of 219 Fusarium isolates, 19 were distinct and the fungal colonies on PDA medium showed the development of pale brown to dark brown pigment. Macro conidia were produced in orange sporodochia from monophialides on branched conidiophores with apical cells tapered and elongated. Chlamydospores were solitary and intercalary. All 19 isolates were morphologically identical, and a representative isolate was used for molecular identification. The ITS rDNA and TEF gene were amplified and sequenced using ITS1/ITS4, TEF1/TEF2primer pairs. The nBLAST search and phylogenetic analysis confirmed that the pathogen was Fusarium equiseti. Pathogenicity tests conducted on 50-day-old maize plants by injecting conidial suspension of F. equiseti produced typical stalk rot symptoms after 15 days of post-inoculation and the pathogen's identity was confirmed by cultural and morphological features after re-isolation. Association of F. equiseti as the causal agent of sheath rot of maize was reported from China. The association of F. equiseti with stalk rot of maize is the first report in India.

A field experiment was conducted to know the gene action and selection of superior parents of velvet bean for hybridization. The heterosis and combining ability study was carried out using 6x6 half diallel mating design excluding reciprocals. Combining ability analysis revealed that magnitude of sca variance was greater than gca variance suggesting the predominance of non additive gene action for most of the traits except days to 50 per cent flowering, number of flowers per inflorescence, number of pods per bunch and 100 seed weight where gca variance was greater than sca variance indicating predominance of additive gene action. Based on gca effects, parents Arka Dhanwantari, IIHR Selection 8 and IIHR Selection 2 were best general combiners for the traits such as number of flowers per inflorescence, pod length, pod weight, number of bunches per plant, number of pods per bunch, dry pod yield and seed yield per plant which can be used in future breeding programme. Specific combining ability studies indicated cross IIHR Selection 2 x IIHR Selection 8 as best specific combiner for the economically important traits viz., pod length, pod weight, dry pod yield per plant and seed yield per plant. The cross IIHR Selection 8 x IIHR Selection 3 was recorded high heterotic effects for dry pod yield per plant, seed yield per plant and test weight of the seed. The cross IIHR Selection 2 x IIHR Selection 8 as superior hybrid as recorded high heterobeltiosis for days to 50% flowering, pod length, pod weight, dry pod yield per plant and seed yield per plant and days to maturity which can be exploited in future breeding programme.

Inter simple sequence repeat (ISSR) markers were used to estimate genetic diversity among 21 samples of Acorus calamus , an endangered medicinal herb from South and North East India. Out of 100 primers screened 14 generated distinct and reproducible DNA fragments. Using these primers, 103 discernible DNA fragments were generated of which 53 (51.5%) were polymorphic and remaining 50 (48.5%) were monomorphic. The amplified PCR fragment size ranged from 450 to 2250 bp. Nei’s genetic diversity ( h ) and Shannon’s index ( I ) among the population were estimated as 0.2005 and 0.2946 respectively. Value for total genotype diversity among population ( H T ) was 0.1893 while within population diversity ( H S ) was found to be 0.0834. The mean coefficient of gene differentiation ( G ST ) was as high as 0.5595 and the gene flow ( N m) was found to be 0.3937; both indicated rapid genetic differentiation among the populations of A. calamus . Analysis of molecular variance (AMOVA) indicated that 43% was attributable to among-populations diversity and the rest (57%) to differences within populations. The UPGMA dendrogram based on Ward’s minimum variance algorithm showed a high level genetic divergence between the populations from South and North Eastern India (∼119 linkage distance) which explains the existence of two geographically distinct populations.

Inter simple sequence repeat markers were used to assess the genetic diversity and population genetic structure in 12 populations ofNothapodytes nimmonianafrom Western Ghats of India. A total of 16 selected primers produced 103 discernible bands, with 76 (73.7%) being polymorphic. The Nei's gene diversity (h) ranged from 0.1166 to 0.2124, with an average of 0.1518 at the population level and 0.2965 at the species level indicating high genetic diversity. The Shannon's index (I) was estimated to be 0.2189 within populations (range 0.1703–0.2947) and 0.4352 at the species level. The analysis of molecular variance showed that the genetic variation was found mainly within populations (73%), but variance among populations was only 27% and its value, ΦPT = 0.271,P GST) was found to be high (0.4882) and the gene flow (Nm) was low (0.5242), confirming the high population genetic differentiation. The unweighted pair-group method using arithmetic average clustering elicited similar results. Based on this, we propose conservation strategy for this plant species.

A. calamus L. is a critically endangered (FRLHT, 2000), semi-aquatic plant of temperate and sub-temperate regions. A. calamus, from the family Araceae, has been valued for its rhizome and fragrant oils, which is being used medicinally to cure diarrhoea, dysentery, digestion, abdominal obstruction and colitis. For rare, endangered and threatened (RET) species that are in decline, in situ conservation may not give adequate support. Biotechnology supports ex situ conservation programs, besides complementing conventional methods, have the potential to broaden the genetic base in species demanding high priority. Acorus calamus rhizome has been used to initiate aseptic cultures, which is a pre-requisite for in vitro conservation. The sterile explants were cut to appropriate size and inoculated into Murashige and Skoog medium (MS full strength and half strength concentration) with and without Naphthylacetic acid (NAA) and Benzylaminopurine (BAP). The explants that responded were transferred into MS medium with BAP and NAA for multiplication and into Murashige and Skoog (MS) medium devoid of growth regulators for medium-term storage (under standard culture conditions). These cultures were incubated at 26±2°C with 31.55 μm -2 s -2 light intensity. For in vitro growth studies, parameters observed include number of shoots, shoot length, number of roots, made at intervals of 1 month, 3 months and 6 months, to establish sub-culture frequency and storage period. Rooted vitro plantlets were hardened successfully using 'Soilrite', which was found to be the best hardening medium, with ca. 99% success. In vitro established cultures of Acorus calamus were relocated to chambers having reduced light and temperature conditions (reduced temperature of 10°C and reduced light of intensity of 2.97 μm -2 s -1 ) to study the effect of storage. Protocols developed for large-scale propagation and in vitro conservation will be discussed.

Nothapodytes nimmoniana Graham; Syn. Mappia foetida (Icacinaceae) an endangered tree species of Western Ghats of India is an excellent source of quinoline alkaloids, camptothecin (CPT), used clinically as such or after derivation as anticancer agents for the treatment of solid tumors. Development of in vitro multiplication and conservation techniques are highly desirable, as there is no reported cultivation or conservation protocols of this endangered species. MS medium with different plant growth regulators (PGRs) were tried to optimize the protocol for in vitro multiplication of this species. Among the various explants tried, only the isolated seed embryos collected from Idukki district of Kerala, showed a positive response on MS with 0.91 μM thidiazuron (TDZ), 3% sucrose, 0.8% agar and pH 5.8 in Standard Culture Conditions (SCC). From regenerating callus, multiple shoots were regenerated and development of somatic embryos was observed on the same medium after 3 week of incubation. After one month of incubation in TDZ medium somatic embryos developed were small, inseparable and on an average of 70 per tube and 5 mm to 15 mm long. Shoot elongation of 2-19 mm was observed on MS basal medium after one month of incubation. One mg/L IBA was ideal for root initiation of the vitro plants. Some the cultures in (SCC) were shifted to low temperature (+10°C) for in vitro conservation. Under reduced temperature and light, in vitro plants grew well (without any subculturing) even after the six months of incubation. Cultures in MS basal medium showed shoot elongation of 5-10 mm compared to MS with TDZ (3-50 mm). The interesting results of growth response of the cultures in low temperature imply that it is possible to conserve the species under low temperature for a longer period without regular subculturing. Protocols for the establishment of in vitro gene bank for these species will be discussed.

A field study was conducted in Aloe vera syn Aloe barbadensis with an objective to determine the effect of various levels of synthetic fertilizers (10:10:10: 20:20:20: 40:40:40: 80:80:80: N:P2O5:K2O kg/ha) on chemical constituents at the inflorescence stage of the plant (12 months old). The active principles were assessed from the gel (mucilaginous tissue of leaf) and juice (yellow exudate from the base of leaf). The results suggested that free o-glycones and o-glycosides were not affected by levels of NPK nutrients applied, but c-glycosides, anhydrous barbaloin and hydroxy anthroquinone derivatives were significantly affected with application of NPK fertilizers at 40:40:40 or 80:80:80 N:P2O5:K2O kg/ha. The recovery of total polysaccharides from gel ranged from 0.52% from control to 0.89% in 40:40:40 applied plots. Anhydrous barbaloin content estimated using HPLC technique and colorimetric methods were comparable Aloe emodin was found absent in all samples. Aloesin content ranged from 10.60 to 13.10% in Aloe juice and there was no significant difference across treatments. The recovery of Aloe juice ranged from 0.050 to 0.066% on dry weight basis.

Storing pollen for future use is an important tool in species that are wild crop relatives, for conservation of genetic resources. The mature male gametophyte of most plant species is desiccation tolerant which render them ideally suitable for storage. A major impact of pollen cryopreservation of threatened plants will be to maintain genetically diverse stocks of pollen collected from wild for future conservation measures, a strategy which can also accomplish conservation of nuclear genetic diversity (NGD) to conserve genetic variation expressed through pollen. This is the only variability that could be tapped under natural situations, especially when information on their breeding behavior is less known. Long term pollen cryopreservation has been attempted successfully in many species for conservation of NGD. Case studies of pollen from five RET (rare, endangered, threatened) plants which require immediate conservation attention viz., Celastrus paniculatus, Cayratia pedata, Oroxylum indicum and pollenia from Decalepis hamiltonii and Holostemma adakodien were investigated for their suitability to cryogenic preservation. Pollen/pollinia of these species after initial viability assessment were cryopreserved by direct immersion in liquid nitrogen. After 1 week of cryostorage, pollen/pollinia were re-assessed for viability. Three species showed no difference in post cryostorage viability. The remaining two species declined in post-cryostorage viability by way of reduced germination when compared to their fresh counterparts. Among the two species with pollinia there was a delayed post-storage germination initiation by 1 and 2 h, compared to initial germination of fresh pollinia. The results indicate that for RET plants investigated in this study, pollen cryopreservation can be encouraged to conserve nuclear genetic variability which could be used with increased efficiency to improve seed set for species recovery, amplification, etc., for eco-rehabilitation/eco-restoration programs.

Medicinal and Aromatic Crops are the source of basic raw materials for pharmaceutical, perfumery, flavor, soap and cosmetic industries and now a days are receiving global attention since they contribute for health security, employment and income generation to millions of people in rural and peri-urban areas. In addition, they contribute to health needs of people in rural communities in alternate systems of medicine, generate additional employment and income, offer opportunities for processing and export enterprises and contribute for national development.