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Tao Deng, Richard J. Abbott, Wenqing Li, Hang Sun and Sergei Volis

Historical processes during the Quaternary are likely to have left a signature on the geographical distribution of intraspecific genetic variation. In particular, high genetic uniqueness could be expected within glacial refugia for multiple species. We aimed to test this for plants in China and whether multi-species hotspots of genetic diversity are good indicators of glacial refugia in this region. From chloroplast DNA haplotype data for 116 species we calculated two local genetic diversity metrics for each species: haplotype genetic richness and genetic uniqueness. From these two, only uniqueness could reliably identify refugia, whereas richness may indicate either glacial refugia or areas recolonized by genetic lineages from different refugia in the postglacial period. Our results suggest the occurrence of numerous cryptic refugia and their likely importance in the maintenance and evolution of the Chinese flora, and indicate that an approach that locates geographic hotspots of genetic diversity data can reliably identify refugia.

Nili Anglister, Yoram Yom-Tov and Uzi Motro

The Mediterranean coastal dune habitat of Israel is diminishing rapidly, mostly due to massive urbanization, changes in habitat characteristics caused by dune stabilization and the presence of Acacia saligna, an invasive species brought to Israel for the purpose of dune stabilization. In this study we document the effect of sand stabilization on the composition of small mammal communities in the Ashdod-Nizzanim sands, Israel. We analyzed differences in species diversity and abundance for species of rodents in four types of habitat: unstable (mobile) sand dune, semi-stabilized dune, inter-dune depression and a plot of the invasive Acacia saligna. Rodent communities were found to undergo gradual changes concurrently with the stabilization of the sands. The mobile dune was the only habitat in which the strict psammophiles Jaculus jaculus and Gerbillus pyramidum were captured in abundance. No species commensal with human were captured neither in the mobile nor in the semi-stabilized dunes. However, in the inter-dune depression there was quite a large representation of Mus musculus, a rodent commensal with humans. The Acacia saligna plot had the lowest number of captures and the lowest rodent biomass calculated, with Mus musculus composing nearly half of the captures. The results of this study demonstrate that stabilization of the sands in Ashdod-Nizzanim area is associated with the disappearance of psammophile rodents and the appearance of species commensal with humans. In order to preserve the habitat for psammophile rodents, measures should be taken to halt the spread of acacia and the continuing stabilization of the sands.

Jitendriya Panigrahi, Saikat Gantait and Illa C. Patel

The present study formulates a method for comprehensive production of vasicinone, a quinazoline alkaloid, from multiple plant parts of in vitro and in-field-grown Justicia beddomei. HPTLC analysis of plant parts was executed with methanolic extract using toluene: butanol: butyl acetate (9:0.5:0.5; v/v/v) as the solvent system. Validation of methodology was accomplished using TLC plates (silica gel 60 F254-pre-coated aluminium sheet) following the ICH manual to maintain accuracy, precision and repeatability with a linearity ranging 2–6 μg/spot. Validation data offers precision to the methodology adapted in the present study (LOD 1 μg/spot and LOQ 3 μg/spot). It was evident that in vitro samples produced relatively higher levels of vasicinone than that of their in-field counterparts. The highest vasicinone (2.07±0.025% of dry weight) production was quantified from in vitro stem, signifying a new resource for the production of vasicinone from identified parts of in vitro and in-field propagated J. beddomei plants.

Subhash Chander, Rajasekharan P.E. and Reju M. Kurian

Annona cv. ‘Arka Sahan’ essentially needs assisted pollination with sugar apple pollen for commercial fruit production. However, there is no perfect synchronization in flowering of the pollen source sugar apple cv. Balanagar with that of cv. ‘Arka Sahan’. So, an attempt was made to store the pollen of the former to assure its availability as and when cv. ‘Arka Sahan’ flowers need to be pollinated. In vitro pollen germination was assessed using different concentrations of sucrose (5%, 10% and 15%) with and without boric acid (100 ppm). Pollen collected on the second day of anthesis showed maximum germination (43.47%) in 5% sucrose + 100 ppm boric acid while those collected on first day of anthesis did not show any germination. Pollen collected at different times of the day showed a rapid decrease in pollen germination from maximum germination at 6 am (36.55%) to no germination at 2 pm. The maximum pollen germination was in 10% sucrose + 100 ppm boric acid combination for the stored pollen as well as pollen collected during late hours of the day. Pollen stored under varying temperatures lost viability within 1 month at 4°C while pollen stored at −196°C in liquid nitrogen retained germination for 2 months. Pollen germination and pollen tube growth were progressively reduced with storage time. Structure of stored pollen examined using Scanning Electron Microscope (SEM), revealed deformed and shriveled pollen structure. The results of this study indicated that the Annona pollen tends to be viable for a period of 2 months.

Yifan Chen, Qian Bai, Funan Ruan and Shuchai Su

The Pistacia chinensis Bunge is traditionally dioecious, and the female trees are more required to grow in practice for oil seed production. The discovery of monoecious P. chinensis Bunge in North China provided good raw materials to study the sex differentiation process. The objective of this study was to identify the differently expressed proteins in flower buds in two key sex differentiation phases in monoecious P. chinensis Bunge. Morphological observation and paraffin section were used to determine the key phenophases, and label-free quantitative technique was used for proteomic analysis. The results showed that the proteins related to oxidative stress resistance up-regulated while proteins involved in photosynthesis down-regulated during the female primordium differentiation in bisexual flower buds of the monoecious P. chinensis Bunge in early March, while proteins related to oxidative stress resistance, ribosome activity, and photosynthetic function up-regulated during the male primordium differentiation in bisexual flower buds of the monoecious P. chinensis Bunge in late May. The most up-regulated proteins all involved in the photosynthesis pathway in both kind of flower buds in late May compared to those in early March, and the down-regulated proteins all involved in the ribosome pathway. The identified differentially expressed proteins such as the Cu/Zn superoxide dismutases may be possible molecular markers for sex determination in monoecious P. chinensis Bunge.

Sachin Kumar Vaid, Prakash Chandra Srivastava, Satya Pratap Pachauri, Anita Sharma, Deepa Rawat, Bhupendra Mathpal, Shailesh Chandra Shankhadhar and Arvind Kumar Shukla

Large scale deficiency of Zn results in low crops yields and the problem of Zn malnutrition in humans and livestock. To economize crop production on Zn deficient soils, two-year field experiments were undertaken with two wheat varieties to evaluate the performance of seed inoculation with a consortium of three bacterial strains in combination with varying doses of Zn fertilizer applied to 1 year rice crop on yields, Zn concentration and Zn uptake of wheat. Seed coating of wheat with bacterial consortium significantly increased grain yields, Zn concentration and uptake in grains and straw and total Zn uptake over the control. It also helped to increase the apparent recoveries of soil applied Zn fertilizer to 1 year rice by succeeding wheat crops and DTPA extractable Zn in soil after 2 year wheat in comparison to the control. Seed inoculation in combination with low dosage of Zn also significantly decreased phytic acid: Zn ratio but increased methionine concentration in wheat grains.

P.K. Nimbolkar, Reju M. Kurian, K.K. Upreti, R.H. Laxman and L.R. Varalakshmi

Mango is a commercial fruit crop in different parts of the tropical and subtropical world. Commercially important monoembryonic varieties are propagated through grafting onto rootstock seedlings of polyembryonic genotypes that plays an important role in sustained growth and production. Use of salt tolerant genotypes as rootstock to combat the adverse effect of salinity could be helpful for commercial mango production in salt affected areas. Current study was carried out to elucidate the effect of salinity stress induced by NaCl + CaCl2 (1:1 w/w) at 0, 25, 50 and 100 mM concentrations in irrigation water on candidate polyembryonic mango genotypes namely EC-95862, Bappakkai, Vellaikolamban, Nekkare, Turpentine, Muvandan, Kurukkan, Kensington, Olour, Manipur, Deorakhio, Vattam, Mylepelian, Sabre and Kitchener. We studied the morpho-physiological changes of these seedlings under salinity induced stress for determining their relative tolerance by assessing growth parameters such as plant height, number of leaves, leaf area, inter-nodal length, fresh weight of shoot, fresh weight of root, dry weight of shoot, dry weight of root, stem diameter and physiological parameters like photosynthetic rate, transpiration rate, stomatal conductance, number of stomata and stomata length and width, in addition to ABA content in leaves. Our results clarifies that the polyembryonic genotypes Turpentine, Deorakhio Olour and Bappakkai showed less reduction in terms of growth and better maintenance of gas exchange status under higher level of salinity.

Yogesh Kumar Tiwari and Sushil Kumar Yadav

Anti-oxidative system in plants comprising of enzymatic and non-enzymatic antioxidants imparts stress tolerance by scavenging/detoxification of excess reactive oxygen species (ROS) produced under high temperature stress. Present investigation deals with the estimation of metabolites and anti-oxidative enzyme activities in four inbred maize lines; NSJ221, NSJ189, PSRJ13099 and RJR270 in response to high temperature stress imposed at reproductive stage by staggered sowing. An increase in H2O2 and malondialdehyde (MDA) was observed in all the genotypes, however the increase was higher in PSRJ13099 and RJR270. The activities of studied enzymes increased in NSJ189 and NSJ221 while a decrease was observed in PSRJ13099 and RJR270. Under heat stress isoforms of SOD increased in NSJ189 and NSJ221 while a concomitant decrease was observed in PSRJ13099 and RJR270. Two new SOD-isoforms were also observed in NSJ221. GPX showed more number of high mobility isoforms with low activity in NSJ221 and less mobile isoforms with higher activity in both NSJ189 and NSJ221. Whereas, PSRJ13099 and RJR270 showed decrease band intensity of less mobile GPX-isoforms under heat stress. Activity of CAT-isoforms increased to a similar extent across the genotypes under heat stress. In case of non-enzymatic antioxidants, non-protein thiols increased in all the genotypes while the level of carotenoids depleted in all the genotypes except NSJ221. Ascorbate (AsA) levels depleted in PSRJ13099 and RJR270 and increased in NSJ189 and NSJ221 under heat stress. Understanding the intricate regulatory pathways in crop plants under heat stress will help in developing genotypes with enhanced stress tolerance.

Edited by Anne-Laure Decombeix, Lisa Boucher, Elisabeth A. Wheeler and Pieter Baas