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Pollen cryopreservation and cross-compatibility studies to overcome wide hybridization barriers in selected leguminous species

In document 61st Convocation (Page 31-34)

The present study was carried out to investigate floral biology, pollen cryopreservation and cross-compatibility studies to overcome wide hybridization barriers in selected minor legume species. A total of 4 accessions of V.

unguiculata, 12 accessions of V. vexillata., 20 accessions of Lathyrus sativus L. and 3 accessions of L. cicera, comprising both indigenous and exotic ones, representing different morphotypes were studied. The later three species revealed typical characteristic features of Fabaceae. Further, seven developmental stages in V. vexillata and five in L. sativus and L. cicera were identified, with significant variation in days for maturation and flower opening.

Brewbaker and Kwack’s medium with 15% sucrose was optimal for in vitro pollen germination in L. sativus. The pollen viability at anthesis varied and peak stigma receptivity and pollen viability was found in S6 stage of V.

vexillata and in S4 stage of L. sativus and L. cicera. Negative correlation between pollen viability, storage duration and temperature was obtained and only cryopreserved pollen (-196 ºC) showed significantly higher viability, successful pollination, fruit and seed set. Direct cross of V. ungiculata x V. vexillata led to 2- 4 % pod set, and no pod set in reciprocal cross; while in direct and reciprocal crosses of L. sativus x L. cicera, 3 to 7 % pod set occurred.

Presence of pre-fertilization barriers in V. vexillata x V. ungiculata, may be due to the hairiness on stigma causing poor pollen germination and penetration, pre and post-fertilization barriers in V. ungiculata x V. vexillata, L. sativus x L. cicera, L. cicera x L. sativus, may be due to the callose deposition in the transmitting pollen tube in the stylar region and embryo abortion. Embryo rescued with shoot regeneration in five combinations of V. unguiculata × V.

vexillata on MS media, while in Lathyrus, hybrid embryos with only initial shoots were successfully rescued in 7 combinations of L. sativus × L. cicera and 8 combinations of L. cicera × L. sativus on MS as well as modified MS.

The present study provided new data for interspecific crosses of V. unguiculata, V. vexillata, Lathyrus sativus and L. cicera and deep insights into the floral development, pollen biology, and pollination barriers of the later three species. importantly, a novel pollen cryopreservation protocol of L. sativus and V. vexillata has been standardized for long-term conservation, which would aid cowpea and grasspea breeding throughout the year.

Theme 4. Taxonomic studies in PGR

Delineation of Solanum melongena var. incanum l. from S. melongena l. - S melongena var. insanum l. Species complex through morphological and molecular taxonomy

Brinjal (Solanum melongena L.) is the most popular warm season vegetable crops and widely cultivated in South Asia, South East Asia and few African countries. india is the center of origin of brinjal and as a result wide genetic diversity of landraces and wild relatives is observed. With the existing uncertainty on identities of brinjal wild relatives, the present study deals with the identity of Solanum melongena var. insanum L. and Solanum melongena L. - Solanum melongena var. incanum L. accessions deposited in the genebank using morphological descriptors and sequence of DNA based barcoding loci. The accessions were characterized using 41 quantitative and 30 qualitative agro-morphological and taxonomical characters including some of the key characters to differentiate the complex of melongena vs incanum vs. insanum. Out of 27 distinguishing characters, one accession (iC546043) from Solanum melongena var. incanum and one accession (iC531767) from Solanum melongena L.

- Solanum melongena var. insanum L. complex qualified for 18 and 13 characters, respectively. In PC analysis, PC1 and PC2 accounted for 67.3% and 17.4% of the variation, respectively. PC1 contributed maximum for corolla diameter, 5 fruit weight and fruit pedicel diameter whereas PC2 contributed maximum for leaf blade length, leaf blade hairs (abaxial), number of flower prickle (calyx), fruit calyx prickle, plant height, plant spread, number of primary branches, stem diameter, stem prickle/10cm and stem prickle length. Overall, PC1 attributed to fruit characters whereas PC2 attributed to vegetative growth characters. Number of flower prickles (calyx), fruit calyx prickles and stem prickle/10 cm had negative PC1 loading values while the same characters had positive PC2 loading values. The dendrogram grouped all the 89 accessions in one cluster except iC256161 due to its higher fruit weight. Not a single accession was clearly distinguished for any species using the agromorphological and taxonomical characters, rather revealed intermediate types between the wild species. Both the dendrograms drawn using Euclidean distance generated based on agromorphological-taxonomical characters of 89 accessions and through UPGMA based on rbcL molecular sequence of representative 21 accessions showed multiple clustering and revealed that the genebank accessions used in the study are all of intermediate form between the cultivated and wild relatives that exhibited significant gene flow between themselves resulting in intermediate forms. The accessions studied from the national genebank showed intermediate characters in morphology and formed high diverse MP tree through rbcL sequence and can be considered as intermediate forms of “insanum, incanum, melongena” complex.

List of contributing students and Chairperson of their advisory Committee

S. No. Name of the

student Roll

No. Degree M.Sc/


Title of the thesis Chairperson 1. Latief Bashir 21501 M.Sc. Genome-wide association study to identify

QTNS for quality traits, seed parameters and yield related traits in bread wheat under heat stress regime

Dr. Sundeep Kumar

2. Thendral U S 21502 M.Sc. Habitat prediction and mapping of Crop Wild Relatives (CWR) Of Vigna spp. in india us- ing Bioclim model

Dr. Dinesh Prasad Semwal 3. RinkyResma

Panda 21503 M.Sc. Development of cryopreservation protocol of Artocarpus Lacucha Buch.-Ham. - An indig- enous underutilized fruit species

Dr. Sandhya Gupta 4. Shashank H G 21504 M.Sc. Genome-wide association study to identify

significant MTAs for seedling establishment traits in wheat (Triticum aestivum L.)

Dr. Sherry Ra- chel Jacob 5. Sridhar A. 21505 M.Sc. Delineation of Solanum Melongena Var. in-

canum L. from S. Melongena L. - S Melonge- na Var. insanum L. species complex through morphological and molecular taxonomy

Dr. Krishna Kumar Gangopadhyay 6. Rakesh

Kumar Bairwa

10649 Ph.D. Assessment of genetic variation and allele mining for quality traits in aromatic rice lan- draces from indo-Gangetic plains of india

Dr. Mahesh C.

Yadav 7. Deepak D A 11084 Ph.D. In Vitro clonal propagation and cryopreserva-

tion protocol development in Betel L. (Betel vine) for germplasm conservation

Dr. Anuradha Agrawal 8. Chaw

SuSuHtwe 11368 Ph.D. Transcriptomes changes during cryopreser-

vation stages of banana meristems Dr. Anuradha Agrawal 9. Shankar M. 11566 Ph.D. Pollen cryopreservation and cross-compati-

bility studies to overcome wide hybridization barriers in selected leguminous species

Dr. Anuradha Agrawal

In document 61st Convocation (Page 31-34)