Screening new <Emphasis Type="Italic">Arachis</Emphasis> amphidiploids,and autotetraploids for resistance to late leaf spot by detached leaf technique

Cultivated groundnut is susceptible to late leaf spot (LLS) caused by Phaeoisariopsis personata [(Berk. & M.A. Curtis) Aex] and resistance is low to moderate in the primary gene pool of groundnut. Closely related wild species in the secondary gene pool are highly resistant to the disease. All the closely related Arachis species are diploid and cultivated groundnut is a tetraploid. Utilization of diploid Arachis species to transfer LLS resistance is time consuming and cumbersome. New sources of Arachis hypogaea (also called synthetic groundnut) were developed at ICRISAT. These are tetraploids and the present investigation has shown that they are resistant to LLS.     

Proline and Glutamine Improve in vitro Callus Induction and Subsequent Shooting in Rice

This study was conducted to evaluate the effects of proline and glutamine on in vitro callus induction and subsequent regeneration and to develop a reproducible and highly efficient plant regeneration protocol in four rice genotypes, viz. Pawana, Jaya, Indrayani and Ambemohar. Considerable variation in response to plant growth regulators and amino acid supplements used was observed in all the four genotypes. Medium supplemented with proline and glutamine was shown to be superior to medium without proline and glutamine. The best callusing from mature embryo was observed on Murashige and Skoog(MS) medium supplemented with 2.0 mg/L 2,4-dichlorophenoxyacetic acid(2,4-D), 500 mg/L proline and 500 mg/L glutamine. Shoot induction was higher in the callus obtained from medium supplemented with 500 mg/L proline and 500 mg/L glutamine. The highest shoot regeneration frequency(83.2%) was observed on MS medium with 2.0 mg/L benzylaminopurine, 0.5 mg/L 1-naphthaleneacetic acid, 500 mg/L proline, and 500 mg/L glutamine in the callus obtained from MS medium supplemented with 2.0 mg/L 2,4-D, 500 mg/L proline and 500 mg/L glutamine. Among the four genotypes, Pawana has the highest regeneration efficiency(83.2%), whereas the regeneration efficiency of the rest three rice genotypes was in the range of 32.0% to 72.3%. This optimized regeneration protocol can be efficiently used for Agrobacterium mediated genetic transformation in rice.     

Improvement in cooking quality of horse gram (Dolichos biflorus) by pre-soaking treatment with salt solution

Soaking of horse gram (Dolichos biflorus) in a solution of 1.5% NaHCO₃, 0.5% Na₂CO₃, and 0.75% citric acid for 12 h was found to be effective in reducing cooking time from 145 to 27 min. The treatment improved protein digestibility of cooked horse gram from 69 to 78%. Horse gram cooked after pre-treatment with soak solution had 35% less amount of polyphenols than that in untreated cooked samples. The suitability of this treatment for reducing cooking time of several other legumes was evaluated.     

基于GIS的流域土壤侵蚀和产沙量模型（摘选）

基于USLE模型利用地理信息系统（GIS）和遥感（RS）对Wadsa-Chincholi流域年土壤流失量空间分布进行调查。空间输入数据由Arc GIS 9.3和RS（ERDAS IMAGINE 9.3图像处理软件）提供,利用USLE对网格内年均输沙量的空间分布进行预测。USLE参数基本单元的网格单元尺寸（GCS）分别为50 m×50 m、100 m×100 m和200 m×200 m。根据流域出口对年均输沙量进行估算。此外,将利用通用土壤流失方程（USLE）估算的产沙量与观测值进行对比。利用USLE模型预测得到50 m×50 m、100 m×100 m和200 m×200 m的年均输沙量分别为在63.80、18.83和3.67 t（hm2·年）。200 m×200 m GCS预测值与观测得到的产沙量基本相符。因此,在200 m×200 m GCS情况下,利用USLE模型得到的预测结果能够用于对Wadsa-Chincholi流域产沙量空间分布的研究。从水土保持角度来看,研究区域涵盖了侵蚀非常严重、侵蚀严重、侵蚀非常高、高度侵蚀和中度侵蚀类,这都需要引起重视。      

Stability of micropropagated Musa acuminata cv. Grand Naine over clonal generations: A molecular assessment

The present work was undertaken to investigate clonal fidelity of banana (Musa acuminata cv. Grand Naine) regenerants from six different in vitro subculture generations and in the explant suckers by using ISSR and REMAP molecular markers. Both types of markers revealed high degree of monomorphism. Very low variation was observed up to the eighth subculture generation with polymorphic bands being low in both ISSR (0.96%) and REMAP (0.95%) markers. Epigenetic stability was studied by DNA methylation analysis of the eighth subculture generation samples. Single 570 bp methylation sensitive band was absent in two of the fifteen MspI predigested samples, while it was present in HpaII predigested and undigested samples. The results of the investigation confirmed that the micropropagation of banana up to the eighth subculture generation show low variation.     

Differences between Cajanus cajan (L.) Millspaugh and C. cajanifolius (Haines) van der Maesen, the progenitor species of pigeonpea

A study was undertaken to know the difference/diversity between pigeonpea and its closely related wild species C. cajanifolius by studying their morphology, crossability, cytology of the hybrid between the two, and molecular studies. Studies revealed that there are at least 5–6 traits that separate the two species such as flower morphology, pod color and morphology, pod constriction, seed color and strophiole, 100 seed weight that separate C. cajan from C. cajanifolius. Molecular studies revealed that a genetic dissimilarity index value ranging from 0.81 to 0.94 exists between the two species.     

Genetic Diversity and Population Structure in Landraces and Improved Rice Varieties from India

A set of 50 rice genotypes comprising landraces, local selections, and improved varieties were characterized using simple sequence repeat(SSR) and inter simple sequence repeat(ISSR) markers to study genetic diversity and population structure. Following unweighted pair group method with arithmetic mean based clustering using binary data of polymorphic markers, the genotypes were grouped into 5 clusters and 11 sub-clusters, whereas population structure analysis separated 50 rice genotypes into 5 sub-populations. Grouping of rice genotypes showed better resemblance with the pedigree information of the genotypes. Both genetic diversity and population structure analysis separated majority of the improved varieties from landraces and local selections. Some of the SSR markers amplified unique alleles which were specific to a particular genotype and could distinguish them from the rest. The results indicate that these rice genotypes exhibit a higher genetic diversity and can be very useful in rice improvement program.     

Insecticide resistance in Helicoverpa armigera in South India

Cypermethrin, quinalphos, endosulfan and methomyl were bioassayed against strains of Helicoverpa armigera collected from field crops in Andhra Pradesh and Tamil Nadu, South India, during the 1989-90 and 1990-91 cropping seasons. In 1989, high levels of resistance to cypermethrin were recorded in strains from cotton in the cotton-growing regions of Guntur, Andhra Pradesh and Coimbatore, Tamil Nadu, and from pigeon pea near Hyderabad. There was no evidence for resistance to quinalphos or methomyl at that time. In 1990-91 sampling was more extensive and although tolerance to cypermethrin was lower than the previous season, the survey indicated that pyrethroid-resistant populations were present throughout much of Andhra Pradesh. Tolerance to quinalphos had increased slightly in 1990-91, while resistance to methomyl had increased substantially, particularly in the cotton-growing area of Guntur. Endosulfan tolerance had increased slightly compared to strains tested in 1986-88 in an earlier study. The geographic and temporal variations in severity of pyrethroid resistance in H. armigera in Andhra Pradesh are believed to arise because of dynamic interactions between local selection pressure and immigration of resistant and susceptible moths at certain times of the year.     

Light fast monoazo dyes with an inbuilt photostabilizing unit: Synthesis and computational studies

A series of monoazo disperse dyes with a photostablilizing o-hydroxycarbonyl moiety was incorporated resulted in the enhancement of the light fastness properties on polyester and nylon substrates as compared to the dyes that do not possess the photostablilizing moiety. The geometries of the azo and the hydrazone tautomeric forms of all dyes were optimized at B3LYP/6-311+G(d) and electrophilicity index was calculated for propensity of the moiety to absorb electrons. The values of absorption and stability trend of the dyes were in good agreement with the trend of experimental light fastness values. These disperse dyes possess excellent wash fastness and moderate to good sublimation fastness on hydrophobic substrates.