Journal Article

Variation in South African citron watermelon (Citrullus lanatus var. citroides L.H. Bailey Mansf. ex Greb.) landraces assessed through qualitative and quantitative phenotypic traits

Shimelis, Hussein, Ngwepe, Richard Mantlo, Mashilo, Jacob

2021

Overview

Citron watermelon [ Citrullus lanatus var. citroides (L.H. Bailey) Mansf. ex Greb.] is an important genetic resource serving for food, feed, and breeding dessert watermelon ( C. lanatus var. lanatus ) and other cross-compatible species. Wide phenotypic variation exists among South African citron watermelon landraces which are yet to be systematicaly assessed for diverse uses and cultivar design. The objective of this study was to assess phenotypic diversity of citron watermelon landrace accessions of South Africa and to select desirable genotypes with suitable agronomic and horticultual traits for direct production, breeding and conservation. Thirty six citron watermelon landrace accessions were evaluated under field conditions in two seasons using a 6 × 6 alpha lattice design with three replicates. Data on key qualitative and quantitative traits were collected and subjected to non-parametric and parametric statistical analyses. The accessions showed wide phenotypic variation and unique traits for genetic improvement. Positive and significant correlations ( p  < 0.001) were recorded between total fruit yield per plant with plant height ( r  = 0.64), number of harvestable fruits ( r  = 0.70), number of marketable fruits ( r  = 0.73) and marketable fruit yield ( r  = 0.96). Seed yield per plant positively and significantly ( p  < 0.001) correlated with number of male flowers ( r  = 0.68), plant height ( r  = 0.61) and total fruit yield ( r  = 0.79). Prinicipal component analysis identified nine components which accounted for 86.38% of total variation amongst accessions for assessed phenotypic traits. Citron watermelon accessions WWM16, WWM67 and WWM79 were high-yielding suitable for fruit production for food or livestock feed. Accessions namely WWM03, WWM09, WWM16, WWM39, WM64 and WWM76 produced high fruit number and marketable fruit yield per plant which are recommended as parental genotypes for breeding. Furthermore, accessions WWM04, WWM15, WWM24, WWM28, WWM46, WWM66, WWM68, WWM76 and WWM79 were selected with higher seed production for the food or feed industry. The study recommends citron watermelon accessions such as WWM14, WWM16, WWM39, WWM41, WWM67 and WWM79 for use as leafy vegetables owing to their profuse branching ability and longer vine production. Whereas accessions including WWM03, WWM17, WWM35, WWM40, WWM50, WWM67, WWM79 and WWM85 are selected with larger fruit size. Accessions WWM05 and WWM09 are sour-flesh types which are suitable genetic stocks for breeding sweet-and-sour dessert watermelons. Orange-fleshed accessions such as WWM03, WWM04, WWM46, WWM64, WWM66 and WWM67 are recommended for fresh consumption, cooking, processing or variety design. Accessions WWM02, WWM03, WWM08, WWM14, WWM16, WWM23, WWM38, WWM40, WWM41 and WWM67 have red and white seed coat colour which are superior selections to prepare roasted citron watermelon seed snack.

• Publisher: Springer Netherlands,Springer Nature B.V
• Subject: Agriculture / Animal husbandry / Biomedical and Life Sciences / Breeding / Citrullus lanatus / Citrullus lanatus var. citroides / Citrus medica / color / Cooking / Crop production / Crop yield / Cultivars / Desserts / evolution / Feed industry / Flowers & plants / Food / Food industry / fruit size / fruit yield / Fruits / Genetic improvement / Genetic resources / Genotypes / landraces / Lattice design / Life Sciences / Livestock / Livestock feed / Livestock feeds / males / phenotype / phenotypic variation / Phenotypic variations / Plant breeding / Plant Genetics and Genomics / plant height / Plant Physiology / Plant Sciences / Plant Systematics/Taxonomy/Biogeography / Qualitative analysis / Research Article / seed coat / seed yield / South Africa / Statistical analysis / vines / Water melons / watermelons