Storage root formation and development in sweet potato [Ipomoea batatas (L) Lam. Convolvulaceae] is a complex process characterized by the cessation of root elongation, genesis of vascular cambium, anomalous and interstitial cambia, and increase in radial growth by increased cell proliferation and expansion concomitant with the massive deposition of starch and storage proteins that eventually result in storage root enlargement. Phytohormones play a crucial role in the formation of storage roots. Three class I knotted-like homeobox (KNOX1) genes-SRF1, SRF5, and SRF6-modulate carbohydrate metabolism and cell division. The genes Ibkn1 and Ibkn2 activate cytokinin biosynthesis. Transcription factors derived from MADS box genes IbMADS1, IbMADS3, IbMADS4, and IbAGL17 induce signal transduction pathway leading to storage root formation and development. The occurrence of SRD1 transcripts mainly in the actively dividing cells, including the vascular and cambium cells, and the increase in endogenous indole-3-acetic acid (IAA) content and three auxin-inducible AUX/IAA gene transcripts concomitantly with SRD1 transcripts suggest the involvement of SRD1 during the early stage of storage root development. Along with IbMADS1 induction, two storage root marker genes, which encode a major storage protein sporamin and IbAGPase that encodes AGPase for ADP-glucose production in starch biosynthesis, are up-regulated during the early period of storage root development. A class III HD-Zip protein 8 regulating the development of cambia and secondary vascular tissues, a short-root protein that is a key regulator in root 157 radial patterning, meristem maintenance, and asymmetric cell division, the expansin gene IbEXP1 encoding a cell wall loosening protein, genes encoding cyclin A-and cyclin D-like proteins, and five cyclin-dependent kinases are upregulated during storage root formation. Genes encoding ADP-glucose pyrophosphorylase, granule-bound starch synthase, starch synthase, and phosphoglucomutase are up-regulated, whereas genes encoding pyruvate decarboxylase and lactate dehydrogenase are down-regulated during storage root development. The endogenous sucrose levels influence the expression of two AGPase isoforms: ibAGP1 and ibAGP2. The expression of cell wall-bound (extracellular/apoplast) acid invertase activity gene (cwINV) predominates during early period, whereas the expression of cytosolic activity of sucrose synthase gene (SuSy) predominates during later period of storage root enlargement. The competition between lignification and formation of anomalous cambia and the associated starchaccumulating cells determine storage root development. Genes encoding enzymes such as coumaroyl-CoA synthase, caffeoyl-CoA O-methyltransferase, and cinnamyl alcohol dehydrogenase during storage root formation reduce lignification in tissue sections of storage roots.

A B S T R A C TA study was conducted to find out the level of access and usage of ICTs among farmers of Meghalaya state of India. A total of 120 farmers were randomly selected for the study during November 2013 to May 2014. The results showed that majority of the farmers owned mobile phones as well as television and radio. The most frequently used ICT was mobile phone. Mobile phones were widely used by the farmers for social communication, contacting middle men for the marketing of produce and contacting experts on real time basis for getting agricultural advisories. Farmers also reported that mobile phones proved to be useful during health emergencies. Information services on availability of inputs, quality of inputs, and pest and disease management of crops were also used by the farmers through ICTs. Major problems in the use of ICTs by the farmers were lack of confidence in operating ICTs, erratic power supply, low network connectivity and lack of awareness of the benefits of ICTs.

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Genetic variation in Nilagiri sheep, the only apparel wool breed in South India was studied using 25 FAO recommended ovine-specific microsatellite markers. The number of observed alleles ranged from 3 to 8 with a mean of 5 across all loci. The size of alleles ranged from 72 to 228 bp. The frequency of alleles ranged from 0.0104 to 0.5781. In total, 125 alleles were observed at the 25 loci studied. The effective number of alleles ranged from 2.18 to 6.49. The mean number of effective alleles was 3.84 across all loci. All the 25 loci were found to be highly polymorphic. The PIC values ranged from 0.4587 to 0.8277 with a mean of 0.6485. Of 25 microsatellites studied, 17 were in Hardy-Weinberg Equilibrium proportions. The observed heterozygosity ranged from 0.4222 to 1.000 with a mean value of 0.7610 whereas the expected heterozygosity ranged from 0.5415 to 0.8459 with a mean value of 0.7213. Except six loci, the other loci revealed negative within-population inbreeding estimates (F IS ) indicating excess of heterozygotes in the population of Nilagiri sheep.

The aim of the present study was to analyse the influence of year, season and parity on productive and reproductive performances in 110 Soviet Chinchilla and 64 White Giant rabbits under tropical climatic conditions of Tamil Nadu in the period between 2005 and 2009. A total of 731 records for the overall leastsquares means for litter size at birth and weaning, litter weight at birth and weaning, average weight of kit at birth and weaning and pre-weaning growth rate in Soviet Chinchilla rabbits were 5.1±0.1, 3.7±0.1, 256.4±6.9 g, 2465.4±73.6 g, 50.4±0.7 g, 694.1±13.1 g and 15.3±0.3 g/d, respectively, and the values for White Giant rabbits were 5.1±0.1, 4.1±0.1, 259.6±6.1 g, 2432.6±68.7 g, 50.8±0.4 g, 614.6±13.5 g and 13.4±0.3 g/d, respectively. Breed had significant effect on litter size at weaning (P<0.01), average weight of kit at weaning (P<0.05) and pre-weaning growth rate (P<0.01). Year of birth had significant effect on litter size and litter weight at birth (P<0.05), litter size and litter weight at weaning (P<0.01), average weight of kits at weaning and pre-weaning growth rate (P<0.01) in Soviet Chinchilla and White Giant rabbits. Season of birth had significant effect on litter weight at birth and weaning (P<0.05), average weight of kits at birth (P<0.05) and weaning (P<0.01) and pre-weaning growth rate (P<0.01) in both the breeds. Parity had significant effect on litter weight and average weight of kits at weaning (P<0.01) and pre-weaning growth rate (P<0.01). The study revealed that the Soviet Chinchilla and White Giant breeds performed well in the tropical climatic conditions of Tamil Nadu and could be used for profitable meat production. The significant influence of factors such as year of birth and season of birth observed on different production traits emphasises the role played by the management in optimising the realisation of genetic potential under local agro-climatic conditions.

Learning the chemistry of compounds containing carbonyl groups is difficult for undergraduate students partly because of a convolution of multiple possible reaction sites, competitive reactions taking place at those sites, different criteria needed to discern between the mechanisms of these reactions, and no straightforward selection method applicable to all. Factual inaccuracies in some recently used comprehensive introductory organic chemistry textbooks can distract and confuse students. Student interest, combined with some inconsistencies, prompted a systematic comparison of these textbooks, enabling some suggestions for improvement. Students also selected a preferred order of presentation in which carbonyl chemistry should appear for optimal learning: carboxylic acids, aldehydes, ketones, carboxylic acid derivatives, α,β-unsaturated carbonyls, and carbonyl compounds that undergo enol chemistry. This ordering is generally based on a combination of (1) grouping according to the purpose of the functional group, (2) increasing complexity of reactions with a nucleophile, and (3) decreasing carbonyl compound reactivity. In order to facilitate solving carbonyl chemistry problems and understanding these competing factors, information about the reactions is presented in three forms: a text discussion, a Summary Sheet, and a Decision Tree. The recommendations are consistent, descriptive, and pedagogically useful, and they should remedy many discrepancies.

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