Historical perspective of in situ hybridization for the analysis of genomic constitution of plants

In situ hybridization involves hybridization of DNA or RNA probes to the cytological preparations. The technique originally used auto-radiographic labeling to map both repetitive and low copy DNA sequences. The problem associated with this technique was its short half life, lack of safety and long exposure time which hindered its widespread use in DNA hybridization. To overcome these problems, non isotopic in situ hybridization was developed for use in animal and plant species. In the last decade, the development of haptens and fluorochromes enabled simultaneous multicolored detection of differentially labeled probes. Characterization of parental genomes in interspecific hybrids, restructured chromosomes, gene mapping, detecting nature of chromosome pairing, establishing phylogenetic relationship among the species and localizing introgressed segment have been successfully achieved by fluorescence in situ hybridization. Keywords: In situ hybridization, phylogenetic relationship, homoeologous pairin

Identification of leaf rust resistant gene Lr10 in Pakistani wheat germplasm

Leaf (brown) rust is the major disease of wheat in Pakistan and other countries. The disease is more effectively controlled when several rust resistance genes are pyramided into a single line. Molecular survey was conducted to screen 25 Pakistan wheat germplasm for the presence of leaf rust resistance gene Lr10 using specific STS primer. The survey revealed that out of the 25 germplasm/lines grown in Hazara University Botanic garden, 18 genotypes were observed with Lr10 gene, while seven genotypes did not show the presence of Lr10 gene. The identification of Lr10 in Pakistan wheat germplasm will help in accelerating the breeding program in future, including the pyramiding of different resistant genes in wheat varieties.Key words: Wheat, leaf rust, Lr10, molecular markers

Survey of Predatory Coccinellids (Coleoptera: Coccinellidae) in the Chitral District, Pakistan

An extensive survey of predatory Coccinellid beetles (Coleoptera: Coccinellidae) was conducted in the Chitral District, Pakistan, over a period of 7 months (April through October, 2001). A total of 2600 specimens of Coccinellids were collected from 12 different localities having altitudes from 1219.40–2651.63 m. Twelve different species belonging to 9 genera of 3 tribes and 2 sub-families were recorded. Two sub-families, viz, Coccinellinae Latreille, 1807 and Chilocorinae Mulsant, 1846 were identified. The following 8 species belonged to family Coccinellinae Latreille 1807 and tribe Coccinellini Latreille 1807: Coccinella septempunctata Linnaeus, 1758, Hippodamia (Adonia) variegata Goeze, 1777, Calvia punctata (Mulsant, 1846), Adalia bipunctata (Linnaeus, 1758),Adalia tetraspilota (Hope, 1831), Aiolocaria hexaspilota Hope 1851, Macroilleis (Halyzia) hauseri Mader, 1930,Oenopia conglobata Linnaeus, 1758. Only one species namely Halyzia tschitscherini Semenov, 1965 represented tribe Psylloborini of the sub-family Coccinellinae Latreille, 1807. Three species occurred from sub-family Chilocorinae Mulsant 1846 and tribe Chilocorini Mulsant 1846: Chilocorus rubidus Hope, 1831, Chilocorus circumdatus (Gyllenhal, 1808), Priscibrumus uropygialis (Mulsant, 1853). From the aforementioned species 6 were recorded for the first time from Pakistan: Chilocorus circumdatus, Calvia punctata, Adalia bipunctata, Macroilleis (Halyzia) hauseri, Priscibrumus uropygialis, and Oenopia conglobata

Effectiveness of the Administrative Performance of Directly Selected Executive District Officers in Elementary and Secondary Education of KHYBER PUKHTUNKHWA PAKISTAN

Abstrac

Adaptive Responses of Soybean and Cotton to Water Stress: I. Transpiration Changes in Relation to Stomatal Area and Stomatal Conductance

The adaptive responses of soybean and cotton to various irrigation levels were explored in terms of transpiration, stomatal role in transpiration, leaf temperature (Tl) and CO2 assimilation rate (An). Compared with cotton, soybean showed a lower flow rate of stem sap (FRSS), transpiration rate (E), stomatal conductance (gs), stomatal density and An and had a smaller stomatal area but larger leaf area, heavier root dry matter and higher Tl at all irrigation levels. Under water stress conditions, FRSS, E, gs, and An decreased and Tl increased more in soybean than in cotton. Stomatal area decreased in response to water stress though nonsignificantly but stomatal density was not affected by water stress in soybean. Stomatal area decreased significantly in response to water stress in cotton. We concluded that soybean and cotton adapted to water stress differently. Soybean adapted to water stress by reducing transpiration while cotton adapted to water stress by maintaining higher transpiration as compared with soybean. Soybean reduced the transpiration rate by reducing gs. Reduction of gs in soybean was due to reduced FRSS, which might have resulted from the lower root moisture absorption efficiency. The higher transpiration in cotton was due to a higher gs, which was supported by a higher FRSS, larger stomatal area, and probably the diaheliotropism. The higher gs and transpiration rate suppressed the increase in Tl thus preventing the decrease of An in response to water stress

Adaptive Responses of Soybean and Cotton to Water Stress II. Changes in CO2 Assimilation Rate, Chlorophyll Fluorescence and Photochemical Reflectance Index in Relation to Leaf Temperature

Adaptive changes were studied comparatively in soybean and cotton grown in pots under four irrigation conditions i.e. normal irrigation (equal to the evapotranspiration of the crop), and 50%, 25% and 10% of the normal irrigation. In soybean, the maximum quantum yield of PSII (Fv/Fm) was generally higher while the actual quantum yield of PSII (∆F/Fm’) and CO2 assimilation rate (An) were lower than in cotton.The intensity of the decrease in Fv/Fm, ∆F/Fm’ and An by water-stress treatments was larger in soybean than in cotton. The decrease in ∆F/Fm’ in soybean under water stress was accompanied by a significant increase in non-photochemical quenching (NPQ) and significant decrease in photochemical reflectance index (PRI). Chlorophyll content decreased significantly under severe water stress only in soybean. The increase in leaf temperature (Tl) in response to water stress was significantly larger in soybean than in cotton. Tl was highly and negatively correlated with Fv/Fm, An, PRI and ∆F/Fm’ while it was highly and positively correlated with NPQ of both crops. Especially in soybean, the correlations of Tl with An, Fv/Fm and PRI were significant. It was concluded that soybean adapted to water stress by dissipating the excess excitation energy thermally with the down-regulation of PSII activity to protect its photosynthetic apparatus from the photodamaging effect of water stress and high Tl. This photoprotective mechanism might be supported by the paraheliotropic leaf movement of the crop. Cotton adapted to water stress by keeping Tl lower to protect the photosynthetic apparatus from photodamage. Probably higher transpiration kept Tl of the crop lower under drought stress