Wild Loquat Research Articles

Chloroplast genomes of Eriobotrya elliptica and an unknown wild loquat “YN-1”

The chloroplast genomes of wild loquat can help to determine their place in the history of evolution. Here, we sequenced and assembled two novel wild loquat’s chloroplast genomes, one is Eriobotrya elliptica, and the other is an unidentified wild loquat, which we named “YN-1”. Their sizes are 159,471 bp and 159,399 bp, respectively. We also assembled a cultivated loquat named ‘JFZ’, its chloroplast genome size is 159,156 bp. A comparative study was conducted with six distinct species of loquats, including five wild loquats and one cultivated loquat. The results showed that both E. elliptica and “YN-1” have 127 genes, one gene more than E. fragrans, which is psbK. Regions trnF-GAA-ndhJ, petG-trnP-UGG, and rpl32-trnL-UAG were found to exhibit high variability. It was discovered that there was a positive selection on rpl22 and rps12. RNA editing analysis found several chilling stress-specific RNA editing sites, especially in rpl2 gene. Phylogenetic analysis results showed that “YN-1” is closely related to E. elliptica, E. obovata and E. henryi.

Haplotype-resolved chromosome-level genome assembly of Ehretia macrophylla

Ehretia macrophylla Wall, known as wild loquat, is an ecologically, economically, and medicinally significant tree species widely grown in China, Japan, Vietnam, and Nepal. In this study, we have successfully generated a haplotype-resolved chromosome-scale genome assembly of E. macrophylla by integrating PacBio HiFi long-reads, Illumina short-reads, and Hi-C data. The genome assembly consists of two haplotypes, with sizes of 1.82 Gb and 1.58 Gb respectively, and contig N50 lengths of 28.11 Mb and 21.57 Mb correspondingly. Additionally, 99.41% of the assembly was successfully anchored into 40 pseudo-chromosomes. We predicted 58,886 protein-coding genes, of which 99.60% were functionally annotated from databases. We furthermore detected 2.65 Gb repeat sequences, 659,290 rRNAs, 4,931 tRNAs and 4,688 other ncRNAs. The high-quality assembly of the genome offers a solid basis for furthering the fields of molecular breeding and functional genomics of E. macrophylla.

Optimisation of nutritional composition of traditional porridges produced from blended pearl millet, cowpeas, and wild loquat and velvet wild medlar fruits

Traditional cereal based porridges have an important role to play in the fight against food insecurity. However, the cereal based porridges are high in energy and are usually deficient in some essential amino acids as well as micronutrients. The objective of the study was to optimise blending ratios of porridges formulated from pearl millet, cowpeas, wild loquat and velvet wild medlar fruit powders to improve the nutritional composition. Twelve formulations of the composite flours were determined using D-optimal mixture design. The ingredients were considered in the ranges of 58 %–66 %, 20 %–30 %, 8 %–15 % for pearl millet flour, cowpeas flour, and fruit powders, respectively. The porridges were analysed for nutritional composition, functional properties, anti-nutritional factors, and sensory acceptability. The results showed significant difference (P < 0.05) in proximate, water absorption capacity, viscosity, reconstitution time, bulk density, mineral, phytate, total phenolic content as well as overall acceptability with changes in ingredient composition. The overall optimum point was in the range of pearl millet (58.82 %), cowpea (26.17 %), fruit powders (15 %) at a desirability of 0.581. In conclusion, optimisation of cereal based porridges with legumes and indigenous fruits enhanced nutrient composition. The porridges can help contribute in improving food insecurity, especially in resource poor communities.

Genome assembly of wild loquat (Eriobotrya japonica) and resequencing provide new insights into the genomic evolution and fruit domestication in loquat.

Wild loquats (Eriobotrya japonica Lindl.) provide remarkable genetic resources for studying domestication and breeding improved varieties. Herein, we generate the first high-quality chromosome-level genome assembly of wild loquat, with 45 791 predicted protein-coding genes. Analysis of comparative genomics indicated that loquat shares a common ancestor with apple and pear, and a recent whole-genome duplication event occurred in loquat prior to its divergence. Genome resequencing showed that the loquat germplasms can be distinctly classified into wild and cultivated groups, and the commercial cultivars have experienced allelic admixture. Compared with cultivated loquats, the wild loquat genome showed very few selected genomic regions and had higher levels of genetic diversity. However, whole-genome scans of selective sweeps were mainly related to fruit quality, size, and flesh color during the domestication process. Large-scale transcriptome and metabolome analyses were further performed to identify differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) in wild and cultivated loquats at various fruit development stages. Unlike those in wild loquat, the key DEGs and DAMs involved in carbohydrate metabolism, plant hormone signal transduction, flavonoid biosynthesis, and carotenoid biosynthesis were significantly regulated in cultivated loquats during fruit development. These high-quality reference genome, resequencing, and large-scale transcriptome/metabolome data provide valuable resources for elucidating fruit domestication and molecular breeding in loquat.

Morphological and Developmental Features of Stone Cells in Eriobotrya Fruits.

Some members of the Rosaceae family, particularly pear, contain stone cells in their fruits. Although stone cells in pear fruits are well studied, relatively little attention has been given to loquat stone cells. Only a few reports have suggested a relationship between stone cell traits and storage and transport tolerance of loquat fruits. Previously, we generated the variety JT8 from the interspecific hybrid of the loquat cultivar Jiefangzhong (JFZ; Eriobotrya japonica Lindl. cv. Jiefangzhong, female parent) and wild Taiwanese loquat (TL; E. deflexa Nakai, male parent). The JT8 fruits had a granular feel, similar to that of pear fruits, due to the presence of stone cells. In this study, the shape, size, development, and distribution dynamics of stone cells of Eriobotrya plants were thoroughly investigated. The results showed that loquat stone cells are brachysclereids and often contain typical branching pits. Loquat stone cells were distributed as both single stone cells and in stone cell clusters (SCCs), and the density of the stone cells near the core was higher than that near the peel. Stone cell density first increased and then decreased during fruit development. These traits noted in Eriobotrya were very similar to those observed in pear, indicating a close relationship between loquat and pear. Moreover, the contents, density dynamics, and aggregation traits of stone cells of the interspecific hybrid JT8 were derived from the male parent (TL). Transgressive segregation was likely exhibited in the content of stone cells and the size of the SCCs. More specifically, the content of stone cells reached 1.61% (w/w). In extreme cases, SCCs of JT8 exceeded 1,000 μm in length and 500 μm in width. This demonstrated that stone cell traits could be transmitted from parent to progeny through interspecific hybridization. The density dynamics of stone cells in two loquat cultivars with different storage and transport tolerances were also investigated, which indicated that the cultivar with more stone cells was more tolerant to storage and transport. We suggest that wild loquat genetic resources containing stone cells in Eriobotrya plants can be used to gradually improve the storage and transport tolerance of loquat fruits.

Habitat distribution of diapriid parasitoid wasps (Hymenoptera, Diaprioidea) in eastern Mozambique

The occurrence of the genera and morphospecies of Diapriidae (Insecta, Hymenoptera) in four habitats (stands) of eastern Mozambique, was studied. The genus Miota is recorded from the Afrotropical region for the first time. Overall, diapriids were represented by 52 morphospecies from 10 genera of the subfamilies Belytinae and Diapriinae. The highest occurrence (140 specimens) and the largest taxonomic diversity (42 morphospecies from 9 genera) were found for the diapriids in the native miombo stand (Brachystegia sp.), followed by the eucalypt, Eucalyptus spp., (92 specimens, 24 morphospecies from 8 genera), the loblolly pine, Pinus taeda, (62 specimens, 19 morphospecies from 7 genera), and the wild loquat (Uapaca kirkiana) stands (40 specimens, 14 morphospecies from 7 genera). The most morphospecies-rich genera were Basalys, Coptera and Trichopria (15, 14 and 7 morphospecies respectively), with Coptera being the most specimen-rich in all samples. The same diapriid morphospecies prevailed in all studied habitats. The abundance estimators ACE and Chao1 predicted 61 (60 in Chao1) species for miombo stand, that is nearly 3.0 times richer than the 22 species estimated for wild loquat, 2.1 (2.6) times richer than the 29 (23) species estimated for loblolly pine and 1.5 times richer than the 40 (39) species estimated for eucalypt. The diapriids of the exotic eucalypt and native miombo stands were most similar, and clustered together with diapriids of the exotic loblolly pine stand.

Climate change reduces the natural range of African wild loquat (Uapaca kirkiana Müll. Arg., Phyllanthaceae) in south-central Africa

Climate change is predicted to threaten biodiversity and the distribution and abundance of species. In Africa and other developing regions, changing distributions and abundances of tree species may have profound effects on livelihoods. The aims of the study were to determine the current continuous distribution of African wild loquat (Uapaca kirkiana Mull. Arg., Phyllanthaceae) and to predict the impact of climate change on the future distribution of the species. A maximum entropy method (Maxent) was used to generate models of the current distribution and for projections under different representative concentration pathways (RCPs). After resampling and correlation analysis, models were generated using 84 occurrence records and nine environmental variables. Results showed that the species has a current continuous distribution in the range of miombo woodlands of south-central Africa, in parts of Angola, southern Democratic Republic of Congo, Malawi, Mozambique, Tanzania, Zimbabwe and Zambia. Projections showed suitable habitat contracting under most RCPs in 2050 and 2070. Range contraction was especially acute under a scenario of no mitigation of greenhouse gas emission, that is RCP8.5. In 2050, the range of the species was forecasted to contract by − 13.9% (RCP2.6), − 5.8% (RCP4.5) and − 14.9% (RCP8.5), with a slight expansion of 1.3% under RCP6.0. In 2070, the range was forecasted to contract by − 17.6% (RCP2.6), − 16.4% (RCP4.5), − 3.7% (RCP6.0) and − 20.6% (RCP8.5). Domestication and establishment in protected areas are some options to mitigate against the forecasted contraction of the natural range of the species.

Ethnobotanical study of the competition between humans and baboons (Papio kindae) for wild fruit trees in the fringe of the Kundelungu National Park, D.R. Congo

Background : This study is the first step of a project addressing the under-researched human-nonhuman primate competition for forest resources. Methods : Ethnobotanical surveys conducted in Lukafu and Mulenga, two villages adjacent to the Kundelungu National Park (K.N.P.), Democratic Republic of Congo, involved 139 purposively selected informants. With a particular emphasis on baboon ( Papio kindae Lonnberg)-edible fruit trees, we collected and analyzed information on the most utilized indigenous trees of the area. These included used parts, types of utilizations, acquisition, and perceptions of availability. Results : A total of 26 indigenous tree species, nine of which are baboon-edible, were utilized the most by respondents. Tree products are collected from surrounding miombo woodlands of the K.N.P. mainly for energy (firewood and charcoal) supply and medicinal purposes. Of the nine baboon-edible species, four are used for two or more purposes and three do not have alternative resources. Conclusions : We conclude that the local people: (i) depend on indigenous trees, mainly for energy supply and medicinal uses, and (ii) observe a multipurpose and indispensable character, as well as decreasing tendencies in the main fleshy-fruited trees of food interest for baboons. Therefore, tackling tree cover losses in such a context implies the improvement of access to both non-wood renewable energy sources and quality health services. Towards the alleviation of the anthropogenic pressure on forests resources at the periphery of the K.N.P., two species of both multipurpose status for humans and high food interest for Kinda baboons deserve a particular attention. As an alternative to wild fruits collection, the domestication of the Wild loquat tree Uapaca kirkiana and the Monkey orange tree Strychnos cocculoides will not only improve households’ livelihoods, but also contribute to mitigating the competition for forest resources between humans and baboons. Keywords : Miombo woodlands, Indigenous trees, Wild fruit trees, Ethnobotanical uses, Kinda baboon, Human-Wildlife Conflicts, Park-adjacent Communities, Kundelungu National Park.

Functional characterization of GI and CO homologs from Eriobotrya deflexa Nakai forma koshunensis.

The first report of the cloning and characterization of the flowering time-regulating genes GI and CO homologs from loquat. Flowering time is critical for successful reproduction in plants. In fruit trees, it can also influence the fruit yield and quality. In the previous work, we cloned the important florigen one EdFT and two EdFDs from wild loquat (Eriobotrya deflexa Nakai forma koshunensis); however, the upstream transcription factors are still unknown. The photoperiod pathway genes GIGANTEA (GI) and CONSTANS (CO) have been reported to mainly regulate FT expression in model plants. In this work, we first cloned photoperiod pathway orthologs EdGI and EdCO from E. deflexa Nakai f. koshunensis. Phylogenetic analysis showed they are highly conserved to those from Arabidopsis. They are mainly expressed in the leaves. The EdGI and EdCO were localized in the nucleus. Their expression showed in photoperiodic regulation, while the EdCO transcripts reached the peak at different periods from that of CO in Arabidopsis. Moreover, EdCO significantly activated the EdFT promoter activity. In the transgenic Arabidopsis, downstream-flowering genes like FT and AP1 were obviously upregulated, and consequently resulted in early-flowering phenotype compared to the wild type. These data revealed that the EdGI and EdCO may play a similar role as GI and CO in Arabidopsis, and regulate flower initiation in loquat.

Identification of 21 novel S-RNase alleles and determination of S-genotypes in 66 loquat (Eriobotrya) accessions

As observed in other self-incompatible species in the Pyrinae subtribe, loquat (Eriobotrya japonica) demonstrates gametophytic self-incompatibility that is controlled by the S-locus, which encodes a polymorphic stylar ribonuclease (S-RNase). This allows the female reproductive organ (style) to recognize and reject the pollen from individuals with the same S-alleles, but allows the pollen from individuals with different S-alleles to effect fertilization. The S-genotype is therefore an important consideration in breeding strategies and orchard management. In an attempt to optimize the selection of parental lines in loquat production, the S-RNase alleles of 35 loquat cultivars and their 26 progeny, as well as five wild loquat species, were identified and characterized in this study. The best pollinizer cultivar combinations were also explored. A total of 28 S-alleles were detected, 21 of which constituted novel S-RNase alleles. The S-haplotypes S2 and S6 were the most frequent, followed by S 29 , S 31 , S 5 , S 24 , S 28 , S 33 , S 34 , S 32 , and S 15 , while the rare alleles S 1 , S 9 , S 14 , S 16 , S 17 , S 18 , S 19 , S 20 , S 21 , S 22 , S 23 , S 27 , and S 35 were only observed in one of the accessions tested. Moreover, the S-genotypes of five wild loquat species (E. prinoides, E. bengalensis, E. prinoides var. dadunensis, E. deflexa, and E. japonica) are reported here for the first time. The results will not only facilitate the selection of suitable pollinators for optimal orchard management, but could also encourage the crossbreeding of wild loquat species to enhance the genetic diversity of loquat cultivars.

Footprints of domestication revealed by RAD-tag resequencing in loquat: SNP data reveals a non-significant domestication bottleneck and a single domestication event

BackgroundThe process of crop domestication has long been a major area of research to gain insights into the history of human civilization and to understand the process of evolution. Loquat (Eriobotrya japonica Lindl.) is one of the typical subtropical fruit trees, which was domesticated in China at least 2000 years ago. In the present study, we re-sequenced the genome of nine wild loquat accessions collected from wide geographical range and 10 representative cultivated loquat cultivars by using RAD-tag tacit to exploit the molecular footprints of domestication.ResultsWe obtained 26.4 Gb clean sequencing data from 19 loquat accessions, with an average of 32.64 M reads per genotype. We identified more than 80,000 SNPs distributed throughout the loquat genome. The SNP density and numbers were slightly higher in the wild loquat populations than that in the cultivated populations. All cultivars were clustered together by structure, phylogenetic and PCA analyses.ConclusionThe modern loquat cultivars have experienced a non-significant genetic bottleneck during domestication, and originated from a single domesticated event. Moreover, our study revealed that Hubei province of China is probably the origin center of cultivated loquat.

The variation of NAD+-SDH gene in mutant white-fleshed loquat

Loquat (Eriobotrya japonica Lindl.) can be divided into yellow- and white-fleshed cultivars by flesh color. However, a Dongting loquat mutant, which involved bud sport and growing white-fleshed fruit in the central region of the trunk (as wild loquat bears yellow-fleshed fruits naturally), was discovered in the preliminary study. The study cloned the coding sequence (CDS) of NAD+-dependent sorbitol dehydrogenase (NAD+-SDH) gene from the selected materials of mutant loquat, wild loquat and other nine loquat cultivars/accessions, and found that the CDS of NAD+-SDH gene from the mutant loquat, other than the rest two types of materials, had three single nucleotide polymorphisms (SNPs) loci; in addition, the amino acid encoded at variation loci changed accordingly. NAD+-SDH plays an active role in converting sorbitol into fructose in loquat cultivars. For the mutant white-fleshed loquat, the activity of NAD+-SDH rises first and then drops, the sorbitol content decreases steadily, and its fructose content is higher than that in wild loquat from coloration to maturation stage. As demonstrated by the real-time fluorescence quantification PCR analysis, the expression level of NAD+-SDH gene at maturation stage is about 5-fold lower than wild type. It may be assumed that, the three SNPs loci might lead to excessive conversion of sorbitol into fructose under the catalytic action of NAD+-SDH of white-fleshed mutant loquat at maturation stage, resulting in the increase of fructose content and reduced expression abundance of mRNA after transcription. Besides, NAD+-SDH gene may be related to flesh color and carbohydrate variation of white-fleshed mutant loquat.

Inhibitory effect of ursolic acid and oleanolic acid from Eriobotrya fragrans on A549 cell viability in vivo.

Loquat [Eriobotrya japonica (Lindl.)] is a traditional Chinese medicine, which has been used as an anti-inflammatory and for curing chronic bronchitis among other potential applications. Extracted ursolic acid (UA) and oleanolic acid (OA) from wild loquat were previously found capable of suppressing the proliferation of A549 cells in vitro. In the current study, nude mice were used to determine the inhibitory effect of UA and OA on tumor formation in vivo. The results demonstrate that UA and OA reduced the proliferation of A549 cells in nude mice, and increased the expression of Bid while decreasing the protein levels of MMP-2, Ki-67, and CD34. In this study, we identified potential antitumor activity in a wild loquat extract containing UA and OA, which demonstrates that traditional Chinese medicine may have a role in treating certain types of cancer.

Ursolic Acid and Oleanolic Acid from Eriobotrya fragrans Inhibited the Viability of A549 Cells

Loquat {Eriobotrya japonica (Lindl.)}, a kind of Chinese herb, has many efficacies such as anti-inflammatory, antimicrobial and curing chronic bronchitis. However, reports on the pharmacological action of wild loquat extract are limited. In this work, the A549 cell line was selected to study the inhibitory effect of ursolic acid and oleanolic acid (UA, OA) from the leaves of E. fragrans. Results showed that UA/OA inhibited A549 cell viability and induced apoptosis in a dose and time dependent manner. The cell fraction in the G0/G1 phase dramatically increased under treatment with UA/OA. Data showed that UA activated the expression of PARP. UA and OA down-regulated MMP-2 and Bcl-2; on the contrary, they up-regulated Bid. This work demonstrated that UA/OA extracted from wild loquat leaves can significantly inhibit the viability of A549 cells.

Molecular evidence for natural hybridization between wild loquat (Eriobotrya japonica) and its relative E. prinoides

BackgroundInterspecific hybridization has long been recognized as a pivotal process in plant evolution and speciation. It occurs fairly common in the genera of the subtribe Pyrinae. In Eriobotrya, a small tree genus of Pyrinae, E. prinoides var. daduheensis has been recognized as either a variety of E. prinoides, a natural hybrid between E. prinoides and E. japonica, or a variety of E. japonica. However, to date, there has been no convincing evidence on its status.ResultsFour nuclear genes and two chloroplast regions were sequenced in 89 individuals of these three Eriobotrya taxa from two locations where they coexist. A few fixed nucleotide substitutions or gaps were found in each of the investigated nuclear and chloroplast loci between E. japonica and E. prinoides. Of the 35 individuals of E. prinoides var. daduheensis, 33 showed nucleotide additivity of E. japonica and E. prinoides in at least one nuclear gene, and 10 of them harboured nucleotide additivity at all the four nuclear genes. Most haplotypes of E. prinoides var. daduheensis were also shared with those of E. japonica and E. prinoides. In the two chloroplast regions, 28 and 7 individuals were identical with E. japonica and E. prinoides, respectively.ConclusionsOur study provides compelling evidence for a hybrid status for E. prinoides var. daduheensis. Most hybrid individuals are later-generation hybrids. Both E. japonica and E. prinoides can serve as female parent. Differential adaptation might maintain the species boundary of E. prinoides and E. japonica in the face of hybridization and potential introgression.

Genetic Diversity of Loquat [Eriobotrya japonica (Thunb.) Lindl.] Native to Guizhou Province (China) and Its Potential in the Genetic Improvement of Domesticated Cultivars

Loquat is an important commercial specialty fruit tree crop in China, and as a result, there is significant interest in its genetic improvement. Wild loquat, native to China, provides a remarkable genetic resource for breeding improved varieties. Guizhou Province in southwest China contains many natural populations of loquat in its rural areas. In the present study, we analyzed the genetic diversity of native loquat growing throughout Guizhou Province together with wild relatives and domesticated loquat using a set of 20 informative SSR markers. Molecular analysis identified four gene pools, with gene pool I representing cultivated genotypes and gene pool IV containing wild relatives and native surveyed accessions. Approximately 10.8 % of the samples collected from Guizhou Province are feral forms derived from cultivated genotypes, whereas 24.9 % are most closely related to wild species. The remaining 64.3 % of the gene pool is intermediate genotypes derived from spontaneous crosses between wild native forms and cultivated loquat.

Changes in Cell Ca2+ Distribution in Loquat Leaves and Its Effects on Cold Tolerance

Calcium has been associated with improved cold tolerance in many crops. The aim of this study was to investigate the changes in leaf cell <TEX>$Ca^{2+}$</TEX> distribution and cell organelle ultrastructure of loquat (Eriobotrya japonica Lindl.) plants in response to cold stress at <TEX>$-3^{\circ}C$</TEX>, using transmission electron microscopy (TEM). Two loquat accessions, Zaozhong 6 (a commercial cultivar) and oakleaf loquat (a wild relative) were used. Cold tolerance, as measured by leaf browning rate, was higher in oakleaf plants, and calcium treatment improved cold tolerance in both species. Cold stress first induced inward transport of <TEX>$Ca^{2+}$</TEX> from the intracellular space. Then, the imported <TEX>$Ca^{2+}$</TEX> was aggregated around the chloroplast membrane, finally entering the chloroplast. This pattern of <TEX>$Ca^{2+}$</TEX> distribution in leaf cells occurred earlier in Zaozhong 6 than in the wild loquat. With increasing time of cold exposure, the chloroplast membranes of Zaozhong 6 leaves were damaged, blurred and even disappeared, while those of wild oakleaf loquat leaves maintained their structure longer. In Zaozhong 6, cold stress induced a clear cavity between poorly structured granal thylakoids and vesicles appearing inside the chloroplast, while in oakleaf leaves cold stress had little effect on the ultrastructure of chloroplasts (although chloroplast membranes looked blurred). Loquat leaves accumulated free calcium ions around chloroplasts in response to cold stress, with earlier calcium accumulation occurring in the cold-sensitive cultivar Zaozhong 6 than in wild oakleaf loquat. These results demonstrate that these two loquat species have differences in both cold tolerance and calcium accumulation dynamics.

Genetic Diversity and Identity of Chinese Loquat Cultivars/Accessions (Eriobotrya japonica) Using Apple SSR Markers

Loquat (Eriobotrya japonica) is an underutilized fruit crop that originated in China and for which only a small number of molecular markers are available. This number can be increased by identifying apple SSRs that are transferable to loquat cultivars/accessions to provide new insight into the level of genetic diversity within loquat and synteny with apple. We evaluated 71 apple SSR markers distributed across 17 linkage groups, and identified 39 SSRs transferable to loquat. Testing 54 loquat accessions, from Japan, Spain, four provinces in China, and two wild species gave a total of 155 different alleles with a mean value of 3.38 per locus. The mean effective number of alleles was 2.21, and the mean observed heterozygosity was 0.47. These values indicate a high degree of genetic diversity in the set of Chinese loquat accessions analyzed. Unweighted pair-group method analysis based on simple matching coefficent clustered the accessions into two groups, cultivated and wild loquat. The cultivated loquat can be subdivided into three subgroups which generally reflect their geographic origin in China. The Spanish cultivars clustered with those of the Jiangsu and Zhejiang provinces. A core set of five SSR markers could distinguish most accessions.

Screening wild Eriobotrya species as rootstocks for loquat

SummarySix wild species of Eriobotrya were evaluated as rootstocks for domesticated loquat. Twelve-month-old seedlings of Oak leaf loquat (an Oak Leaf loquat ‘Zaozhong No. 6’ hybrid) and wild Fragrant loquat (E. fragrans Champ) had higher root-to-shoot fresh weight (FW) ratios than other wild species. When the domesticated loquat, ‘Zaozhong No. 6’, was grafted onto seedlings of six different wild loquat species, differences in compatibility were observed. Graft compatibility was lower for all combinations compared to ‘Zaozhong No. 6’ grafted onto domesticated loquat seedlings. When wild Henry loquat was used as a rootstock, delayed incompatibility was observed. Differences in soluble sugar contents (SSC) between scion and rootstock were observed, and there was a significant negative correlation between graft compatibility and the difference in SSC values. The influence of the rootstock on anatomical changes at the graft union were observed using a scanning electron microscope (SEM). Wild rootstocks also influenced scion growth, fruit bearing, and fruit quality. Graft combinations which used wild Fragrant loquat as the rootstock had increased cold tolerance and improved scion growth. Wild Fragrant loquat therefore appears to have value as a rootstock for domesticated loquat.

Fruit Variability and Relationships between Color at Harvest and Quality during Storage of Uapaca kirkiana (Muell. Arg.) Fruit from Natural Woodlands

The full commercial potential of wild loquat [Uapaca kirkiana (Muell. Arg.)], a fruit that is widely used for food and income in parts of Africa, is restricted by its short shelf life and variability in postharvest quality. We have evaluated within and among tree variability in fruit size and color at harvest, and changes of color, soluble solids concentrations (SSC) and pulp deterioration during storage, of fruit harvested during the maturation period. The relationships between fruit shape, size, seed number and SSC of fruit harvested at the ripe stage of maturity was also assessed. Size and color of fruit within and among trees at harvest varied greatly within the same location on the same harvest date. The a* values (redness) were more variable than for other color attributes, reflecting a range of fruit colors from greenish to brown. During a 6 day storage period, fruit color lightness and yellowness decreased, while redness increased, and variation in color attributes decreased. Although fruit color intensified during storage, the SSC of fruit after ripening was linked more with fruit color at harvest, with mean concentrations ranging from 6.7% to 13.8% among trees. When fruit were harvested four weeks later and categorized by color at harvest, SSC varied from 11.8% in greenish-yellow fruit to 14.5% in browner fruit. Pulp deterioration of stored fruit harvested unripe was observed by 6 days. The SSC of fruit harvested when ripe was not significantly correlated with shape, size or seed number. These observations have important implications for germplasm selection and collection of U. kirkiana for domestication purposes. Timing of harvest and/or postharvest sorting of fruit is likely to reduce variability in SSC during the postharvest period.