On several alkaline calcareous soils, Zn and Cu deficiency occurred mainly ill lowland rice (Oryza sativa L.) and was rarely found in wheat (Trilicum aestivum L.). Zinc and Cu requirement of plants was not responsible as the critical Zn and Cu contents ill tops of the two plant species were almost similar i.e. 17.4, 6.5 and 14.5, 5.6 ppm respectively. Neither did rice absorb Zn and Cu less efficiently. On the contrary, their rates of absorption in rice were double than in wheat. They were 22.2, 6.3 and 10.2, 3.3 ng atoms/g fresh root/h respectively in the two plant species. Flooded soil conditions appeared to be responsible for Zn and Cu deficiency in rice as their deficiency was found maillIy in plant samples collected from continuously flooded fields. The mechanism is not known.Both Zn and Cu inhibited uptake of each other in wheat on most of the soils. In rice, only applied Zn depressed Cu uptake but Cu had generally little effect on Zn uptake. Little Cu inhibition of Zn uptake in lowland rice seems to be related to flooded soil conditions. The mechanism is yet to be known. The antagonising element accentuated the deficiency of the other element both in wheat and rice and severely reduced their yields on soils marginal to deficient in Zn or Cu supplies. I t is recommended that their soil availability status should be thoroughly considered before their fertilizers are applied.

A rapid and efficient protocol is outlined for in vitro propagation of muskmelon (Cucumis melo L.) Shoot tips, nodal segments and cotyledonary nodes from in vitro grown seedlings were used as explants. The explants were inoculated on MS medium fortified with different combinations and concentrations of growth regulators viz., BAP, NAA, GA 3 and IBA for multiple shoot regeneration. Effective result was found on MS medium supplemented with 2.0 mg/l BAP, in which 90% and 70% cultures induced multiple shoots from nodal segments and shoot tip explants, respectively. Whereas, 70% cultures of cotyledonary nodes were found to induced shoots on MS medium with 1.5 mg/l BAP + 0.1 mg/l GA 3 . In vitro regenerated shoots were subcultured on half strength MS medium supplemented with different concentrations of IBA and NAA for successful root induction and the effective result (up to 70%) was found in medium with 1 mg/l IBA. Well rooted in vitro grown plantlets were acclimatized in sandy soil, where as 70% plantlets survived.

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Abstract:The effect of external application of phytohormone on explants viz., shoot tips and nodal segments of ash gourd (Benincasa hispida L.) was tested on the frequency of shoot and root induction. Shoot tips and nodal segments were cultured on MS medium supplemented with different concentrations and combinations of cytokinins (BAP, Kinetin), auxin (IBA, NAA) and gibberellic acid (GA 3 ) for multiple shoot formation and root induction. The highest number (up to 90%) of multiple shoot formation was obtained from the shoot tips in MS medium fortified with 1.5 mg/l BAP + 0.2 mg/l GA 3, where average number of shoots per culture was 5.55. In case of nodal segment, better response (up to 78%) for shoot multiplication was found in MS with 2.0 mg/l BAP + 0.2 mg/l GA 3. The concentration of 1.0 mg/l IBA was found to be most effective for root initiation in microshoot developed from both types of explants. Rooted plantlets were acclimatatized and established in sandy soil with good survival rate.Key words: Organogenesis, ash gourd, MS medium, shoot tips, nodal segments mvivskt PvjKz govi KvÊkxl© I ce© vsk G·c− v›U e¨envi K ‡i KvÛgy Kz j I gj Drcv` ‡b dvB ‡Uvni ‡gv ‡bi cÖ ‡qv ‡Mi e¨vwn¨K cÖ fve cix ¶v Kiv n ‡q ‡Q| eûgy Kz j Ges gj Rb¥vevi D ‡Ï ‡k¨ KvÊkxl© Ges ce© vsk¸ ‡jv GgGm wgwWqv ‡gi mv ‡_ wewfboe Nb ‡Z¡ i I wgkÖ ‡Yi mvB ‡UvKvBwbÝ (weGwc I KvB ‡bwUb), Aw·b (AvBweG I GbGG) Ges wR ‡eª wjK GwmW (wRG 3 ) mn ‡hv ‡M KvjPvi Kiv n ‡q ‡Q| 1.5 wgwjMÖ vg/wjUvi weGwc + 0.2 wgwjMÖ vg /wjUvi wRG 3 ni ‡gvb¸wj GgGm wgwWqv ‡gi g ‡a¨ e¨envi K ‡i KvÊkxl© †_ ‡K me ‡P ‡q †ewk (90% ch© šÍ ) eû-KvÛgy Kz j Drcv`b m¤¢ e n ‡q ‡Q Ges †hLv ‡b KvjPvi cÖ wZ gy Kz j msL¨v `u vwo ‡q ‡Q 5.55| ce© vs ‡ki † ¶ ‡Î KvÛgy Kz j Drcv` ‡bi Rb¨ 2.0 wgwjMÖ vg/wjUvi weGwc + 0.2 wgwjMÖ vg/wjUvi wRG 3 e¨envi K ‡i fvj dj cvIqv †M ‡Q (78% ch© šÍ )| Dfq ai ‡bi G·c− v ‡›Ui † ¶ ‡Î 1.0 wgwjMÖ vg/ wjUvi Nb ‡Z¡ i AvBweG e¨envi K ‡i ¶zª KvÛgy Kz j †_ ‡K me© vwaK gj Drcv`b cwijw ¶Z n ‡q ‡Q| wkKo MRv ‡bv AYy Pviv¸ ‡jv ‡K evjy hy ³ gvwU ‡Z Lvc LvIqv ‡bv Ges ¯' vqxKiY Kiv n ‡q ‡Q| G ‡`i †eu ‡P _vKvi nvi h ‡_ó fv ‡jv|