國立虎尾科技大學 |

Studies on Anthracnose Resistance in Watermelon Germplasm.

Record Type:	Language materials, manuscript : Monograph/item
Title/Author:	Studies on Anthracnose Resistance in Watermelon Germplasm./
Author:	Patel, Takshay Kishorbhai.
Description:	1 online resource (198 pages)
Notes:	Source: Dissertations Abstracts International, Volume: 81-10, Section: B.
Contained By:	Dissertations Abstracts International81-10B.
Subject:	Agriculture. -
Online resource:	click for full text (PQDT)
ISBN:	9781392686102

Studies on Anthracnose Resistance in Watermelon Germplasm.
Patel, Takshay Kishorbhai.

Studies on Anthracnose Resistance in Watermelon Germplasm. - 1 online resource (198 pages)

Source: Dissertations Abstracts International, Volume: 81-10, Section: B.

Thesis (Ph.D.)--North Carolina State University, 2019.

Includes bibliographical references

Anthracnose, caused by the pathogen Colletotrichum orbiculare, is a significant disease of cucurbits around the world. Anthracnose has been a major challenge in the USA for watermelon (Citrullus lanatus) production since the early 19th century. Anthracnose is particularly destructive in the southeast region of the USA, where summer rains favor disease infection. Four races cause anthracnose in watermelon, but commercial cultivars are resistant to only three.Many studies identified anthracnose resistant accessions by screening subsets of the watermelon germplasm, with the last in 1994. No new resistant sources have been reported for 25 years. From 2016 to 2018 we screened the watermelon germplasm collection of 1408 PI accessions and ten commercial cultivars, using anthracnose race 1 and 2. Plants were screened in the greenhouse, field and growth chamber. For race 1 there were four replications in the greenhouse, two replications in field and two replications in the chamber. For the race 2 screening there were two replications in the greenhouse. Predicted means were estimated using mixed models for each environment. We identified resistant accessions for both races. We also observed that race 2 is more virulent than race 1. Further, subsets of the most resistant and susceptible accessions were retested for both races. The most resistant accessions to race 1 were PI635712 (C. lanatus), PI385964 (C. lanatus), PI186489 (C. mucosospermus), PI482251 (C. lanatus) and PI482250 (C. lanatus). The most resistant accessions to race 2 were PI500303 (C. amarus), PI482293 (C. amarus), PI482333 (C. amarus), PI244018 (C. amarus) and PI494817 (C. amarus).We studied the inheritance of resistance using biparental cross populations. We developed two populations from the crosses of 'Charleston gray' x 'New Hampshire Midget' (For race 1 resistance) and PI189225 x 'New Hampshire Midget' (For race 2 resistance). We screen six generations from each cross: Parent 1, Parent 2, F1, F2, Backcross Parent 1 and Backcross Parent 2. Resistance against both races is dominant over susceptibility and segregates as a single gene.We estimated heritabilities from two types of populations, 1) the designed biparental cross population, and 2) the germplasm with unaccounted population structure. In the biparental cross, the narrow-sense (h2) and broad-sense (H2) heritability for race 1 resistance were 0.639 and 0.885, respectively. While the h2 and H2 for race 2 were 0.545 and 0.802, respectively. Due to the lack of a population structure, we only estimated H2 from the germplasm data. The H2 for race 1 resistance in greenhouse and chambers were 0.3405 and 0.146, respectively. The H2 for race 2 resistance in the greenhouse was 0.3743.

Electronic reproduction.
Ann Arbor, Mich. :
ProQuest,
2024

Mode of access: World Wide Web

ISBN: 9781392686102Subjects--Topical Terms:

660421
Agriculture.
Index Terms--Genre/Form:

554714
Electronic books.

Studies on Anthracnose Resistance in Watermelon Germplasm.
LDR:04005ntm a22003257 4500 001 1148997
005 20240930130024.5
006 m o d
007 cr bn ---uuuuu
008 250605s2019 xx obm 000 0 eng d
020 $a 9781392686102
035 $a (MiAaPQ)AAI27809660
035 $a (MiAaPQ)NCState_Univ18402036431
035 $a AAI27809660
040 $a MiAaPQ $b eng $c MiAaPQ $d NTU
100 1 $a Patel, Takshay Kishorbhai. $3 1475107
245 1 0 $a Studies on Anthracnose Resistance in Watermelon Germplasm.
264 0 $c 2019
300 $a 1 online resource (198 pages)
336 $a text $b txt $2 rdacontent
337 $a computer $b c $2 rdamedia
338 $a online resource $b cr $2 rdacarrier
500 $a Source: Dissertations Abstracts International, Volume: 81-10, Section: B.
500 $a Advisor: Miller, Grady;Balint-Kurti, Peter;Quesada, Lina;Ashrafi, Hamid;Wehner, Todd.
502 $a Thesis (Ph.D.)--North Carolina State University, 2019.
504 $a Includes bibliographical references
520 $a Anthracnose, caused by the pathogen Colletotrichum orbiculare, is a significant disease of cucurbits around the world. Anthracnose has been a major challenge in the USA for watermelon (Citrullus lanatus) production since the early 19th century. Anthracnose is particularly destructive in the southeast region of the USA, where summer rains favor disease infection. Four races cause anthracnose in watermelon, but commercial cultivars are resistant to only three.Many studies identified anthracnose resistant accessions by screening subsets of the watermelon germplasm, with the last in 1994. No new resistant sources have been reported for 25 years. From 2016 to 2018 we screened the watermelon germplasm collection of 1408 PI accessions and ten commercial cultivars, using anthracnose race 1 and 2. Plants were screened in the greenhouse, field and growth chamber. For race 1 there were four replications in the greenhouse, two replications in field and two replications in the chamber. For the race 2 screening there were two replications in the greenhouse. Predicted means were estimated using mixed models for each environment. We identified resistant accessions for both races. We also observed that race 2 is more virulent than race 1. Further, subsets of the most resistant and susceptible accessions were retested for both races. The most resistant accessions to race 1 were PI635712 (C. lanatus), PI385964 (C. lanatus), PI186489 (C. mucosospermus), PI482251 (C. lanatus) and PI482250 (C. lanatus). The most resistant accessions to race 2 were PI500303 (C. amarus), PI482293 (C. amarus), PI482333 (C. amarus), PI244018 (C. amarus) and PI494817 (C. amarus).We studied the inheritance of resistance using biparental cross populations. We developed two populations from the crosses of 'Charleston gray' x 'New Hampshire Midget' (For race 1 resistance) and PI189225 x 'New Hampshire Midget' (For race 2 resistance). We screen six generations from each cross: Parent 1, Parent 2, F1, F2, Backcross Parent 1 and Backcross Parent 2. Resistance against both races is dominant over susceptibility and segregates as a single gene.We estimated heritabilities from two types of populations, 1) the designed biparental cross population, and 2) the germplasm with unaccounted population structure. In the biparental cross, the narrow-sense (h2) and broad-sense (H2) heritability for race 1 resistance were 0.639 and 0.885, respectively. While the h2 and H2 for race 2 were 0.545 and 0.802, respectively. Due to the lack of a population structure, we only estimated H2 from the germplasm data. The H2 for race 1 resistance in greenhouse and chambers were 0.3405 and 0.146, respectively. The H2 for race 2 resistance in the greenhouse was 0.3743.
533 $a Electronic reproduction. $b Ann Arbor, Mich. : $c ProQuest, $d 2024
538 $a Mode of access: World Wide Web
650 4 $a Agriculture. $3 660421
655 7 $a Electronic books. $2 local $3 554714
690 $a 0473
710 2 $a ProQuest Information and Learning Co. $3 1178819
710 2 $a North Carolina State University. $3 845424
773 0 $t Dissertations Abstracts International $g 81-10B.
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=27809660 $z click for full text (PQDT)