Fluorescence in situ Hybridization and Southern Blot Analyses on Leymus racemosus and Related Species

Fluorescence in situ hybridization (FISH) was carried out in somatic cells of racemosus (lam.) Tzvel. and Thinopyrum junceum ( Savul. & Rayss) A. Love using Th. bessarabicum ( Savul. & Rayss) A. Love genomic DNA as probe. Fourteen pairs of chromosomes in L. racemosus gave positive signal, and only seven of fourteen pairs of chromosomes in Th. junceum showed signal. In FISH probed with PHv62, the chromosomes in Th. bessarabicum and L. racemosus hybridized with PHv62, whereas Th. Bessarabicum showed positive signal in four pairs of chromosomes, and the latter in thirteen pairs of chromosomes. No positive signal was observed in chromosomes of Psathyrostachys juncea (Fisch.) Nevski and Th. junceum. The results of Southern hybridization probed with PHv62 were similar to those of in situ hybridization. Twelve alien chromosome lines of T. aestivum-L, racemosus were detected by PHv62 probing. In most of the alien chromosome lines, PHv62 hybridized in fragment of Leymus chromosomes, except for the line containing chromosomes 5Lr # 1 and 1 1Lr # 1. It is inferred that Th. bessarabicum may involve in the formation of species. Non the less, significant changes have occurred during the evolution of Leymus genomes.     

Access and Identification of Intergeneric Hybrid Between Brassica juncea×Crambe abyssinica

An intergeneric hybrid between Brassica juncea (L.) Coss. x Crambe abyssinica Hochst. ex R. E. Fries was obtained for the first time through routine method combined with embryo rescue. The inductivity of hybrids was 2.1%. In many respects the Fl hybrid resembled either its maternal or paternal parent br both. Consequenfiy, retarded growth, wrinkled leaves and rudimentary anthers in Fl plant were observed. Fl pollen varied in size and 10% ~ 15% were of the paternal pollen type,i.e. ,4-colpate. Fl pollen viability was low and 12% ~ 25% of pollens was viable, with a mean of 18.5%. The chromosome number of Fl somatic cell was 63 which was intermediate between the two parents. Most of pollen mother cells had 63 chromosomes. Analysis of isozymes further confirmed that the F1 hybrid combined the paternal characteristic bands.     

Plant Regeneration from Protoplasts of Brassica Juncea L.

Protoplasts isolated enzymatically from epicotyl and growing tip of Bressica juncea divide to form callus on Kp8 medium. Plant regeneration is obtained from protoplast- derived callus of on MSD3 medium. High concentration of inositol in differentiation medium stimulates plant or shoot regeneration from the epicoty protoplast origin.     

Involvement of Asada-Halliwell Pathway During Phytoremediation of Chromium (VI) in Brassica juncea L. Plants

Brassica juncea (Indian mustard) L. plants were exposed to different concentrations (0.0, 0.1, 0.3 and 0.5 mM) of Chromium (Cr) and harvested after 30 and 60 days of sowing for the analysis of growth parameters, metal uptake and oxidative stress markers. Significant accumulation of Cr (VI) by B. juncea L. plants resulted in the reduced growth and modulations in the pool of various biochemical stress markers. The toxic effects of Cr (VI) on growth and other stress markers (protein content, lipid peroxidation and antioxidative enzymes viz.SOD, CAT, POD, APOX, GR, DHAR and MDHAR) in B. juncea L. were observed to be concentration and time dependent. Effect of Cr (VI) on biochemical parameters was differential and their maximum activities of SOD, POD, APX, GR, DHAR and lipid peroxidation were recorded at 0.5 mM concentration in 30 days old plants. Whereas, trend in the activities of most of the stress markers was reversed in 60 days old plants. The results obtained from the study suggested that Cr (VI) stress inhibited growth of B. juncea L. plants is directly interrelated with its accumulation and resulted in the modulation in activities of various stress markers.     

中国春ph2b突变体×华山新麦草F1自交和回交一代细胞遗传学研究

用中国春ph2b突变体（Triticum aestivum L.cv.Chinese Spring）与华山新麦草（Psathyrostachys huashanica Keng）杂种F1的部分进行自交,而另一部分与3个不同的普通小麦品种以及中国春ph2b突变体进行回交,并对自交和回交一代的形态学和细胞学进行研究.结果表明：（1）含有AABBDDNs的自交F2的花粉母细胞减数分裂中期Ⅰ平均单价体数都在7以上,说明来自华山新麦草的Ns基因组可引起普通小麦ABD基因组中某一个（几个）同源组发生不联会或联会消失;（2）在回交一代（F1×CS、F1×CSph2b）中,平均单价体数都在7以下,说明其中的ph2b基因起到了促进染色体配对的作用;而在回交一代（F1×J-11、F1×郑麦-9023）中,则表现正常,与理论一致;（3）在所有自交和回交一代中,减数分裂期间均出现染色体桥、落后染色体、三分孢子体、多分孢子体以及微核等各种染色体异常行为,说明Ns基因组引起了所得材料细胞学上的不稳定性.从总体上讲,回交比自交能更快地恢复ph2b基因促进部分同源染色体配对的作用,为染色体重组提供更多的机会,期望在后代中获得新种质.     

Differential expression of DAHP synthase and chorismate mutase isozymes during rhizogenesis of Brassica juncea cultured in vitro

The regulatory patterns of two of the enzymes of the shikimate pathway. 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase (DAHP synthase or DS. EC 4. 1. 2. 15) and chorismate motase (CM, EC 5. 4. 99. 5), were investigated using in vitro cultures of Brassica juncea at two stages, viz. undifferentiated, proliferating callus and the root-forming callus. Our studies revealed the presence of the two isozymes of DAHP synthase, DS-Mn and DS-Co. in undifferentiated callus. However, during the rhizogenesis of the callus DS-Mn was absent. Similarly, for chorismate mutase, whereas both the isozymes CM-1 and CM-2 were present in undifferentiated callus only CM-2 was detected at rhizogenesis. The possible involvement of these isozymes in callus growth and rhizogenesis is discussed.     

Floral nectaries and nectar production in brown mustard (Brassica juncea) and white mustard (Sinapis alba) (Brassicaceae)

 The dynamics and abundance of nectar secretion as well as sugar productivity were studied in flowers of brown mustard (Brassica juncea) cv. Małopolska and white mustard (Sinapis alba) cv. Borowska. Moreover, floral nectaries were examined under LM and SEM. In both cultivars lateral and median pairs of nectaries secreted nectar. However, differences were found in morphology and activity of these pairs. The lateral nectaries produced more nectar than the median ones. Nectar secretion started at loose bud and peaked during anther dehiscence. Average amount of nectarsecreted by 100 flowers of cv. Małopolska and cv. Borowska were 119.9 mg and 134 mg. Mean concentration of nectar was 26.7% and 23.4%, respectively. One hundred flowers of cv. Małopolska and cv. Borowska secreted 28.4 mg and 24.9 mg of sugars in nectar. Estimated sugar productivity per 1 ha of crop was 65.5 kg and 71.2 kg, respectively. Received August 28, 2002; accepted November 2, 2002 Published online: June 2, 2003     

Effect of gibberellic acid on carbonic anhydrase,photosynthesis, growth and yield of mustard

The plants of mustard (Brassica juncea L.) were treated with 0, 25 and 50 ΜM gibberellic acid (GA₃) at three fully developed leaf stage (30 d after sowing). Effect of GA₃ on carbonic anhydrase activity, photosynthetic rate, leaf area index and dry mass was studied at 50, 70 and 90 d after sowing. At harvest 1000 seed mass, pod number and seed yield were recorded. GA₃ treatment (50 ΜM) enhanced all the characteristics studied.