Maneesh Mishra

In vitro clonal propagation of bael (Aegle marmelos Corr.) CV. CISH- B1 through enhanced axillary branching

Rapid clonal micropropagation protocol of Aegle marmelos (L.) Corr. cv. CISH-B1 was achieved by nodal stem segment of mature bearing tree. Three centimeter long shoots having one axillary bud excised from 10–15th nodal region of shoots during September gave quick in vitro bud burst (5.33 days) when cultured on MS medium supplemented with BAP, 8.84 μM + IAA 5.7 μM. The maximum number of proliferated shoots (9.0/explant) were obtained on same medium supplemented with BAP 8.84 μM + IAA 5.7 μM. The micro shoots were rooted (100 %) on + IAA 5.7 μM. In vitro rooted plants were acclimatized on autoclaved coconut husk containing plant salt mixture and under shade net house (50 % shade 70–80 % RH). The plants were established in the field after acclimatization. The micropropagated plants were tested for its genetic fidelity using 13 RAPD, 3 ISSR and 2 DAMD primers. Profile obtained by all the three Single Primer Amplification Reaction (SPAR) technique from mother tree and micropropagated plants revealed genetic integrity of micropropagated plants with that of mother tree.

In vitro screening of guava plantlets transformed with endochitinase gene against Fusarium oxysporum f.sp. psidii

Mishra M., Jalil S.U., Mishra R.K., Kumari S., Pandey B.K. (2016): In vitro screening of guava plantlets transformed with endochitinase gene against Fusarium oxysporum f.sp. psidii. Czech J. Genet. Plant Breed., 52: 6–13. Guava wilt disease is a severe threat to guava growers all over the world. It is caused by the soil-borne fungus Fusarium oxysporum f.sp. psidii. To control the disease, the Trichoderma-endochitinase gene was first introgressed into guava (Psidium guajava L.). The transgenic plantlets were screened in vitro for resistance against the wilt pathogen. Six-months-old genetically transformed plants raised in cocopeat under in vitro conditions were inoculated with a 7-days old culture of F. oxysporum f.sp. psidii. The presence of the pathogen in the cocopeat medium was confirmed by cultural as well as PCR analysis using species-specific primers. The roots of transgenic plants were wounded to facilitate the entry of the pathogen. The histopathological analysis revealed the presence of mycelium in vascular bundles. However, none of the plants showed symptoms of wilt disease during the investigation. In vitro pathogen inhibition assay and subsequently spore germination assay revealed that the crude leaf extract of transformed plants inhibited the germination of fungal conidia. The leaf tissue studied for expression of endochitinase revealed that two transgenic plants showed very high activity of N-acetyld-glucosamine (0.741 and 0.738 μM/min/μg of protein, respectively) which clearly indicated that transgenic plants could not develop any symptoms of wilt disease due to overexpression of endochitinase.

Micropropagation of certain underutilized fruit crops: a review

Abstract Micropropagation is a proven means of producing millions of identical plants under a controlled and aseptic condition, independent of seasonal constraints. It not only provides economy of time and space but also gives greater output and allows further augmentation of elite disease free propagules. India is homeland of many important yet underutilized fruit crops such as Indian gooseberry (Emblica officinalis Gaertn), bael (Aegle marmelos Corr.), jackfruit (Artocarpus hetrophyllus L.), tamarind (Tamarindus indica L.) and jamun or black plum (Syzygium cuminii L. Skeels.). Most of these crops have medicinal value and are suitable for growing under marginal situations. The commercial production of these crops is restricted due to the shortage of desirable planting material. Micropropagation can play an important role in rapidly increasing new cultivars of these fruit crops. This review paper outlines the work done on micropropagation of these fruit crops.

Begomoviruses Associated with Horticultural Crops

The horticultural crops are severely threatened by many insects, pests and diseases. In this backdrop, viral diseases assume much greater significance as most of these viral diseases are transmitted through insects. The source of resistance for these viral diseases is scanty. Begomoviruses affect a large number of vegetables and few fruit crops. Begomoviruses cause significant crop losses in horticultural crops like tomato, okra, chilli, papaya, brinjal, cassava, squash, sweet potato, potato, etc. Despite the amount of efforts that has gone into the control of begomoviruses, sustained resistance has not been acquired in many crops. Obtaining crops resistant to begomoviruses is very difficult because the insect vector is whitefly (Bemisia tabaci) which develops resistance against insecticides, and it is increasingly spreading over large parts of the world. Molecular markers and other genomic information are allowing more precision breeding for greater tolerance to viral diseases in general and begomoviruses in particular. This chapter highlights many fruit and vegetable crops which are affected by begomoviruses.