Pranab Hazra

Breeding Okra for Higher Productivity and Yellow Vein Mosaic Tolerance

Improving yield and ensuring its sustainability under adverse conditions through resistant hybrids is the major objective of heterosis breeding in okra (Abelmoschus esculentus L. Moench). A study was undertaken to determine gene action, heterobeltiosis, and combining ability for 15 characters through a Line × Tester mating design in okra. Nonadditive gene action controlled all characters studied. Crosses showing high specific combining ability (sca) and yield involved parents showing high general combining ability for plant height, number of nodes on the main stem, number of leaves per plant, fruit diameter, fruit weight, and number of fruits per plant. Parental lines and hybrids were categorized according to disease reaction. The hybrids ‘VNR Green’ × ‘Shagun’ and ‘Barsha Laxmi’ × ‘Parbhani Kranti’ were selected on the basis of their mean (per se) performance, heterosis manifested in them, and sca effects. These hybrids could be used commercially due to high yield and low percentage disease index values for yellow vein mosaic virus (YVMV) disease.

Breeding Eggplant for Higher Productivity and Bacterial Wilt Tolerance

Eggplant (Solanum melongena L.) has the potential for improvement through heterosis breeding, which can be further utilized for development of desirable recombinants. A Line × Tester mating design was used to determine heterosis over better parent, combining ability, and gene action for 11 characters in eggplant. Crosses showing high specific combining ability (sca) and yield involved parents showing high general combining ability (gca) for fruit weight, fruit diameter, or fruit length. Two hybrids, ‘VNR-218’ × ‘BCB-11’ and ‘Arka Nidhi’ × ‘KS-331’ were selected on the basis of their per se (mean) performance: heterosis and the sca effects. These hybrids could be used commercially due to high yield and low percentage disease index (PDI) values for bacterial wilt disease. The preponderance of nonadditive gene action was evident for control of all characters studied. Parental lines and hybrids were categorized according to disease reaction. Average large vessel area of stems and roots of the hybrids was negatively correlated with PDI. Larger vessel area in the vascular bundle needs to be considered in the selection of hybrids for resistance to bacterial wilt disease.

Characterization of Genetic Resources and Identification of Selection Indices of Brinjal (Solanum melongena L.) Grown in Eastern India

Characterization of Genetic Resources and Identification of Selection Indices of Brinjal (Solanum melongena L.) Grown in Eastern India Thirty five diverse genotypes of brinjal collected from different parts of Eastern India were characterized as per the documented descriptors and were evaluated for their morphological and yield component characters during autumn-winter season. All the brinjal genotypes under study showed highly significant variations among twelve quantitative traits. However, a wide range of days to 50% of flowering (47-79), fruit length (8.70 -23.90 cm), fruit girth (2.67-10.30 cm), fruit weight (52.33-319.37 g), number of marketable fruit per plant (4.33-12.00) and marketable fruit yield per plant (0.39-1.68 kg) among the genotypes was observed. Three characters namely, fruit weight, plant height and days to 50% of flowering exhibited high heritability and genetic advance indicating that such situation may arise due to the action of additive genes controlling the characters. The genotypic and phenotypic correlations agreed closely with each other. Fruit weight and fruit girth exhibited significantly positive correlations with marketable fruit yield per plant. Among the eleven yield component traits, fruit weight and number of marketable fruits per plant showed highly positive direct effect on marketable fruit yield per plant. Attention should be paid on selection based on marketable fruit weight and number of marketable fruits per plant for marketable yield improvement of brinjal. Charakterystyka Zasobów Genetycznych Oraz Identyfikacja Wskaźników Selekcji u Psianki Podłużnej (Solanum melongena L.) Uprawianej We Wschodnich Indiach Trzydzieści pięć różnych genotypów psianki podłużnej zebrane z różnych stron Indii Wschodnich scharakteryzowano pod względem udokumentowanych deskryptorów oraz oceniono pod względem ich cech morfologicznych i składowych plonu w sezonie jesiennozimowym. Wszystkie badane genotypy psianki podłużnej wykazały bardzo istotne zróżnicowanie pod względem dwunastu cech ilościowych. Zaobserwowano szeroki zakres zróżnicowania pod względem takich parametrów jak liczba dni do 50% kwitnienia (47-79), długość owocu (8.70 -23.90 cm), obwód owocu (2.67-10.30 cm), masa owocu (52.33-319.37 g), liczba owoców nadających się do sprzedaży na jedną roślinę (4.33-12.00) oraz plon handlowy na roślinę (0.39-1.68 kg). Trzy cechy, mianowicie, masa owocu, wysokość roślin oraz liczba dni do 50% kwitnienia wykazywały wysoki stopień dziedziczności i postęp genetyczny wskazując na to, że sytuacja ta może być powodowana działaniem genów addytywnych kontrolujących te cechy. Korelacje genotypowe i fenotypowe zgadzały się ściśle ze sobą. Masa owocu i obwód owocu wykazywały istotnie pozytywne korelacje z plonem handlowym na roślinę. Pośród jedenastu cech składowych plonu, masa owocu oraz liczba owoców handlowych na roślinę wykazały wysoce pozytywny bezpośredni wpływ na plon handlowy owoców na roślinę. Należy więc zwracać uwagę na selekcję w oparciu o handlową masę owocu oraz liczbę owoców handlowych na roślinę w celu polepszenia plonu handlowego psianki podłużnej.

Peroxidase and polyphenoloxidase activities and phenol content in fruit of eggplant and their relationship to infestation by shoot and fruit borer.

The shoot and fruit borer (Leucinodes orbonalis Guen.) does severe damage to eggplant (Solanum melongena L.). In order to predict the level of fruit infestation and perhaps correlate it to specific biochemical characteristics, the basis of resistance against the shoot and fruit borer in eggplant was investigated. Seven cultivars of eggplant were sampled at 10, 15, 20, and 25 days after flowering (DAF) for peroxidase (PO) and polyphenoloxidase (PPO) activity and at 15, 20, and 25 DAF for phenol content. Stepwise multiple regression analysis revealed that there was a lack of correlation between fruit infestation and PO activity. However, a correlation between fruit infestation; PPO activity at 15, 20, and 25 DAF; and phenol content at 15 and 20 DAF was observed. Principal components analysis indicated that BCB-38 was the best performing cultivar and can likely be used as improved genetic material in future breeding programs.

Indigenous Leafy Vegetables: A Potential Source of β-Carotene and Ascorbic Acid

Leafy vegetables provide essential minerals, vitamins, and amino acids. A survey was conducted in eastern India to document plant species grown for leafy vegetables or collected from field margins or as weeds in other crops that are used as leafy vegetables. Twenty-two plant species belonging to 14 families were recorded as being used as leafy vegetables. Most had high β-carotene and ascorbic acid contents and could be used to alleviate problems of malnutrition and undernutrition. The leaf amaranth (Amaranthus blitum L.) and water spinach (Ipomoea aquatica Forsskal) had very high β-carotene and ascorbic acid contents. Further research on their nutritional potential is needed for their conservation.

Heterobeltiosis, potence ratio and genetic control of processing quality and disease severity traits in tomato

Five inbred lines of tomato were crossed in a half diallel fashion to estimate the combining ability, mode of gene action, extent of heterobeltiosis and dominance effects in the inheritance of fruit yield, processing qualities and disease severity traits. A preponderance of non-additive gene action was detected for all studied characters except fruit weight, indicating that heterosis breeding is an appropriate strategy for their improvement. Maximum heterobeltiosis was observed for the percent disease index (PDI) of tomato leaf curl viruses (ToLCV), followed by the number of locules per fruit, PDI of early blight, fruit yield per plant, lycopene content of fruit, vitamin C content of fruit, total soluble solids content of fruit and acidity content of fruit. Partial- to over-dominance effects were involved in the inheritance of the studied traits. Three lines (CLN 2777E, BCT-115 and CLN 2777F) were identified as potential donors. We recommend that two hybrids (CLN 2777 F × CLN 2777 E and CLN 2777E × Ailsa Craig fulgens) would be appropriate for commercial use following further evaluation of their traits, as they exhibit desirable horticultural traits, particularly in the tropics.

Floral Biology and Interspecific and Intergeneric Crossability of Teasle Gourd

Information on fruit setting in teasle gourd [Momordica subangulata Blume subsp. renigera (G. Don) WJJ de Wilde] has received little attention, and the precise nature of its breeding system has never been described. A study was undertaken on the pollination mechanism, fruit setting, and interspecific and intergeneric crossability for genetic improvement of teasle gourd. The first flower produced by the male clone reached full bloom 75 days after emergence from the soil; those produced by female clones required an average of 53 days. Number of nodes producing the first flower varied from plant to plant and subsequent flowers also did not develop in any definite sequence. The time required by male and female flower buds to reach anthesis was 15 and 10 days, respectively. Opening of either type of flower occurred between 6 and 7 am, and dehiscence of anthers began at time of opening of female flower. The stigma became receptive 12 hours before anthesis. No fruit set was obtained by hybridization between teasle gourd and other cucurbits, indicating little likelihood for recombination of desirable characters from others cucurbits into teasle gourd using fresh pollen.

Evidence of Economic Heterosis and Genetic Control of Fruit Yield and Yellow Vein Mosaic Virus Disease Severity Traits of Okra

Evidence of Economic Heterosis and Genetic Control of Fruit Yield and Yellow Vein Mosaic Virus Disease Severity Traits of Okra) Ten diverse genotypes of cultivated and wild species were crossed in half diallel fashion to produce 45 F1 hybrids to determine mode of gene action, extent of economic heterosis and dominance effect, and to estimate combining ability for eight quantitative traits. Predictability ratio revealed overwhelming response of non-additive gene action for controlling fruit length, number of fruits per plant, and fruit yield per plant; additive gene effects for days to 50% flowering, while both additive and non-additive genetic control for node number at first flowering, fruit weight, fruit girth, and PDI of YVMV disease. Appropriate breeding strategies for improvement of studied traits are highlighted here. Significant standard heterosis over two commercial hybrids, Shakti and Abantika was comparatively lower in magnitude for fruit yield per plant (4.62 % and 17.59 %, respectively) and higher in magnitude for PDI of YVMV disease (-71.28 % and -72.28 %, respectively). Partial- to overdominance effects were involved in the inheritance of the studied traits. BCO-1 and 11/RES-6 were identified as potential donors for future use. The study could able to identify an outstanding hybrid (BCO-1 × Arka Anamika) having high tolerance both under field and artificial conditions. This hybrid would definitely make a room in okra growing zones of the tropics after critical testing..

In vitro Teasle Gourd Pollen Germination and Pollen Tube Development as Affected by Sucrose, Boric Acid, and Inorganic Salts

ABSTRACT The rapid rate of pollen tube formation in vitro exhibited by some plant species has become a model system for studying growth and development in plants during the past decades. In vitro pollen germination and pollen tube characters were examined as they were affected by nutrient media in Teasle gourd [Momordica subangulata Blume ssp. renigera (G. Don) de Wilde]. Concentrations of sucrose or boric acid, applied separately or in combination, and inorganic salts (potassium nitrate, magnesium sulfate, calcium nitrate) were used as growth media. The best pollen germination (49.82%), highest pollen tube length (77.81 μm), and maximum recovery (36.73%) of intact pollen tube were with 20% sucrose + 0.025% boric acid. Use of inorganic salts in low concentrations negated the benefits of sucrose or boric acid. Germination of pollen grain and subsequent growth of pollen tubes are at least in part physiologically independent in this crop. Considerable rupturing of pollen tubes in boron-deficient media and integration of pollen tubes in calcium-rich media occurred. Sucrose and boric acid beneficially influenced pollen germination and pollen tube formation in teasle gourd.

Genetic control of fruit yield and quality characters in tomato genotypes possessing hp-1, ogc, dg, Aft and rin genes

Five inbred lines of tomato possessing one each of the specific genes viz., hp-1, ogc, dg, Aft and rin were crossed in a half diallel fashion to determine the combining ability and gene action of fruit yield/plant, fruit weight and eight important fruit quality characters. Additive genetic component was predominant for TSS, ascorbic acid and anthocyanin contents; both additive and non-additive components was important for fruit yield/plant, fruit weight and lycopene content, and non-additive gene action was overwhelmingly important for pericarp thickness and total sugar content while estimates of both the genetic components was zero for titrable acidity and β-carotene content of fruit. General combining ability effects of the parents corresponded well to their per se performance. Homozygous recessive condition of the genes, hp-1, ogc, dg governed enhanced lycopene content in the fruits. Homozygous Aft/Aft plant had higher anthocyanin content in the fruit than the heterozygous plant indicating additivity of the Aft gene in expressing the character. The hybrid of two widely divergent parent BCT-115 dg/dg x Alisa Craig Aft/Aft emerged as outstanding for both fruit yield and quality which also opened up the possibility of developing tomato hybrid rich in both lycopene and anthocyanin contents. The hybrid BCT-115 dg/dg x BCT-111 rin/rin was also promising for commercial utilization.